Collabora on the same domain, different port

I have a ddns configured on my router that i curently use for nextcloud. I installed the collabora docker and configured the apache proxy on port 2443 and I can reach the collabora server through it, but when I try to open a document it loads for a while then fails. In my apache logs I sometimes (not every time i open a document) get an SSL handshake with remote server failed message. Also in the docker logs I dont get any errors.