Website spits out PR_CONNECT_RESET_ERROR in firefox's incognito

So I have a site that uses letsencrypt and ssl works fine when I'm browsing my site in firefox. The moment I try browsing my site using incognito mode in firefox my browser throws this secure connection failed error and spits out PR_CONNECT_RESET_ERROR.

I can't seem to come to a solution and it only happens in firefox. Chrome & Edge works in both normal & incognito windows.

How exactly do I fix a PR_CONNECT_RESET_ERROR ?

2 Answers

I had the same problem and the solution was for me to enable the ssl_session_cache

I'm using nginx so I had to add the following line in my config:

 ssl_session_cache shared:SSL:10m;

Thank you @Tokk for the answer. For Ubuntu 20.04, I modified /etc/apache2/mods-available/ssl.conf as follows:

 # SSLSessionCache shmcb:${APACHE_RUN_DIR}/ssl_scache(512000) SSLSessionCache shmcb:${APACHE_RUN_DIR}/ssl_scache(10000000)

Then typing sudo service apache2 restart solved the issue!