yup, openlitespeed is installed with rpm packages (apt-get) but still can't get tls 1.3 to work. i've even got OpenSSL 1.1.1a-dev to work on my ubuntu, am i missing something?
The error message ERR_SSL_PROTOCOL_ERROR error indicates that the browser is not able to initiate the secured communication at the moment. It's almost impossible to pin it down to a single cause, it could be almost anything. There is no definite guide for managing this error. However, there are few changes or settings which help you to get rid you of this error.