Use of `delay` in AWS Lambda results in empty response about imposter HOT 3 OPEN

$ time curl https://<endpoint removed>.lambda-url.us-east-1.on.aws/exact-delay
This is a response with a 10s delay
curl   0.01s user 0.02s system 0% cpu 10.527 total

$ hey -z 20s -h2 https://<endpoint removed>.lambda-url.us-east-1.on.aws/exact-delay

Summary:
  Total:	21.2387 secs
  Slowest:	10.8438 secs
  Fastest:	10.0984 secs
  Average:	10.2685 secs
  Requests/sec:	4.7084

  Total data:	3500 bytes
  Size/request:	35 bytes

Response time histogram:
  10.098 [1]	|■
  10.173 [47]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  10.248 [0]	|
  10.322 [0]	|
  10.397 [47]	|■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
  10.471 [1]	|■
  10.546 [0]	|
  10.620 [3]	|■■■
  10.695 [0]	|
  10.769 [0]	|
  10.844 [1]	|■


Latency distribution:
  10% in 10.1100 secs
  25% in 10.1107 secs
  50% in 10.3914 secs
  75% in 10.3936 secs
  90% in 10.3947 secs
  95% in 10.3971 secs
  99% in 10.8438 secs

Details (average, fastest, slowest):
  DNS+dialup:	0.1169 secs, 10.0984 secs, 10.8438 secs
  DNS-lookup:	0.0141 secs, 0.0000 secs, 0.0285 secs
  req write:	0.0000 secs, 0.0000 secs, 0.0001 secs
  resp wait:	10.1507 secs, 10.0984 secs, 10.6197 secs
  resp read:	0.0001 secs, 0.0000 secs, 0.0008 secs

Status code distribution:
  [200]	100 responses