For the context, I don't think it happened under 4.6, but it might also be because one of the providers I use to post had issues just recently.
Anyway, I use 3 separate providers to post. When one provider has issues, I get stuff like that in the end:
[=================================================>] 99 % (76429 / 76441) avg. speed: 13.01 MB/s[Poster #6 {NntpCon #14}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #14
[Poster #6 {NntpCon #13}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #13
[Poster #7 {NntpCon #16}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #16
[Poster #7 {NntpCon #15}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #15
we lost all the connections...
Sleep for 30 sec before trying to reconnect
Pause posting...
[=================================================>] 99 % (76429 / 76441) avg. speed: 12.91 MB/sTry to resume posting
Resume posting...
[=================================================>] 99 % (76440 / 76441) avg. speed: 12.82 MB/s[Poster #5 {NntpCon #12}] Socket Timeout (30000 ms)
[Poster #5 {NntpCon #12}] Connection lost, trying to reconnect! (nb disconnected: 1)
[==================================================] 100 % (76441 / 76441) avg. speed: 12.82 MB/s
[11:19:24.374] Upload size: 50.99 GB in 01:07:52.955 (4072 sec) => average speed: 12.82 MB/s (16 connections on 16 threads)
4 / 76441 articles FAILED to be uploaded (even with 10 retries)...
[=================================================>] 99 % (76438 / 76441) avg. speed: 15.38 MB/s[Poster #2 {NntpCon #3}] Error Socket: The TLS/SSL connection has been closed
[Poster #2 {NntpCon #3}] Connection lost, trying to reconnect! (nb disconnected: 9)
[Poster #5 {NntpCon #6}] Error Socket: The TLS/SSL connection has been closed
[Poster #3 {NntpCon #4}] Error Socket: The TLS/SSL connection has been closed
[Poster #5 {NntpCon #6}] Connection lost, trying to reconnect! (nb disconnected: 9)
[Poster #3 {NntpCon #4}] Connection lost, trying to reconnect! (nb disconnected: 9)
[Poster #1 {NntpCon #2}] Error Socket: The TLS/SSL connection has been closed
[Poster #1 {NntpCon #2}] Connection lost, trying to reconnect! (nb disconnected: 9)
[Poster #4 {NntpCon #5}] Error Socket: The TLS/SSL connection has been closed
[Poster #4 {NntpCon #5}] Connection lost, trying to reconnect! (nb disconnected: 9)
[Poster #0 {NntpCon #1}] Error Socket: The TLS/SSL connection has been closed
[Poster #0 {NntpCon #1}] Connection lost, trying to reconnect! (nb disconnected: 9)
[=================================================>] 99 % (76438 / 76441) avg. speed: 15.37 MB/s[Poster #7 {NntpCon #8}] Error Socket: The TLS/SSL connection has been closed
[Poster #7 {NntpCon #8}] Connection lost, trying to reconnect! (nb disconnected: 9)
[=================================================>] 99 % (76438 / 76441) avg. speed: 14.13 MB/s[Poster #2 {NntpCon #3}] Error Socket: The TLS/SSL connection has been closed
[Poster #2 {NntpCon #3}] Connection lost, trying to reconnect! (nb disconnected: 10)
[Poster #3 {NntpCon #4}] Error Socket: The TLS/SSL connection has been closed
[Poster #3 {NntpCon #4}] Connection lost, trying to reconnect! (nb disconnected: 10)
[Poster #4 {NntpCon #5}] Error Socket: The TLS/SSL connection has been closed
[Poster #4 {NntpCon #5}] Connection lost, trying to reconnect! (nb disconnected: 10)
[Poster #5 {NntpCon #6}] Error Socket: The TLS/SSL connection has been closed
[Poster #5 {NntpCon #6}] Connection lost, trying to reconnect! (nb disconnected: 10)
[Poster #1 {NntpCon #2}] Error Socket: The TLS/SSL connection has been closed
[Poster #1 {NntpCon #2}] Connection lost, trying to reconnect! (nb disconnected: 10)
[Poster #0 {NntpCon #1}] Error Socket: The TLS/SSL connection has been closed
[Poster #0 {NntpCon #1}] Connection lost, trying to reconnect! (nb disconnected: 10)
[=================================================>] 99 % (76438 / 76441) avg. speed: 14.12 MB/s[Poster #7 {NntpCon #8}] Error Socket: The TLS/SSL connection has been closed
[Poster #7 {NntpCon #8}] Connection lost, trying to reconnect! (nb disconnected: 10)
[=================================================>] 99 % (76438 / 76441) avg. speed: 13.07 MB/s[Poster #4 {NntpCon #5}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #5
[Poster #5 {NntpCon #6}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #6
[Poster #0 {NntpCon #1}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #1
[Poster #2 {NntpCon #3}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #3
[Poster #1 {NntpCon #2}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #2
[Poster #3 {NntpCon #4}] Error Socket: The TLS/SSL connection has been closed
Error: disconnected connection: #4
we lost all the connections...
Sleep for 30 sec before trying to reconnect
Pause posting...
[=================================================>] 99 % (76438 / 76441) avg. speed: 12.97 MB/sTry to resume posting
Resume posting...
[==================================================] 100 % (76441 / 76441) avg. speed: 12.96 MB/s
[15:26:16.665] Upload size: 50.99 GB in 01:07:07.503 (4027 sec) => average speed: 12.96 MB/s (8 connections on 16 threads)
1 / 76441 articles FAILED to be uploaded (even with 10 retries)...
The first try was with -x, and the nzb ended up having post IDs that were missing (I checked with nzbverify). Oddly, the second nzb without -x (and also less connections) had no missing post IDs (but maybe they were never written?).
Anyway, I think it would make sense to try with connections from another provider instead of retrying with the same.