TLS handshaking: SSL_accept() failed: error:141EC044:SSL routines:tls_construct_server_key_exchange:internal error

As it looks for now, they use the old SSL approach on Ports 993 and 995. 

SSL Config says:

ssl = yes
ssl_cert = </etc/pki/tls/certs/exim.pem          ( Lets Encrypt R3 based cert ) 
ssl_key = </etc/pki/tls/private/exim.pem   
ssl_dh_parameters_length = 2048
ssl_dh= </etc/dovecot/dh.pem
ssl_cipher_list = PROFILE=SYSTEM


OS: Fedora 32 X86_64  
Ext4 file storage on local disks

Versions:

dovecot-2.3.13-1.fc32.x86_64
openssl-1.1.1i-1.fc32.x86_64