Can't use full SSL in docker

[intlandsupport]

Describe the bug
Despite placing key.pem and cert.pem in /src the SSL is not working. It says, working in flexible SSL mode.

To Reproduce
Place ssl certs in /src as displayed in the docker logs

Expected behavior
load page on https://SERVERIP:8443

ShareS Version
4.5.3

Screenshots
ERR_SSL_PROTOCOL_ERROR

Desktop (please complete the following information):

• OS: Windows 10
• Chrome
• Latest

certs:

ls src/*.pem

src/cert.pem src/key.pem

also a bit more documentation or detailed readme would be nice!

[intlandsupport]

anyone maybe?