testssl error with expired cert chain

[mervincm]

using the testSSL tool
invalid certificate chain error
Trust (hostname) Ok via SAN and CN (same w/o SNI)
Chain of trust NOT ok (expired)

This occurs if i execute via web or via commandline in docker shell

If I test it from the native OS on docker host using script from the dr wetter github site, I don't get the error
Trust (hostname) Ok via SAN and CN (same w/o SNI)
Chain of trust Ok

May be related to the obsolete Let's Encrypt root cert issue from 2021, (as site under test is using a Let's encrypt cert) but I am not sure how to test.