openssl 1.1.1d SSL_read() failed in error log

[q1548]

I use openssl 1.1.1d, SSL_read() failed in error log.
not often, a few, but what does this mean, thanks.

[crit] ... SSL_read() failed (SSL: error:14191044:SSL
routines:tls1_enc:internal error) while processing HTTP/2 connection
[crit] ... SSL_read() failed (SSL: error:14191044:SSL
routines:tls1_enc:internal error) while processing HTTP/2 connection

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,287429,287429#msg-287429