Note down every tool you use in windows and use alternativeto.net to find linux alternatives for them. Thats what I did, saved me what you are going through. Everytime I tried to switch usinf a sifferent method I just ended up using Windows to not deal with the "pain point" of switching
I use Eternity as well, but with the instance reddthat.com as such my saved posts work fine. Maybe try the web page for your instance to see if they work there?
I've found a couple, and the issue seems to stem from some type of cert from goDaddy specifically.
I don't specifically mean the goDaddy site, I mean some sites that have gotten there certs from goDaddy won't work. It will give an ssl error. I believe it is their wildcard cert specifically.
Or even just the navigation buttons being separate from the screen.