I have a Samsung S24+, I am using the penultimate version of Samsung Internet Browser(Stable), and I can login without confirming any cookies consent, from two points:
A) By clicking the conext menu and selecting forums and by the main-page before the actual forum, and none points me to revoke/accept anything. I am using AdGuard+Home, and I could had face this issue if it was a login problem, where the users must accept/customize cookies but I don't, same applies to my personal computer too.
Now on Apple system things differ because of how restrictive the storage space itself is. You could potentially try to make sure "Block cookies" is disabled within the main browser, or check the cross-site settings.
Uh, this is the way Apple always was. They got something against first/third party cookies, and globally reinforce to make it so secure, that sometimes it just breaks website entirely. Alternative? Microsoft Edge.
Behaves very competently, I know because my wife has a IPhone 15 and I've installed this, and she says its as fast as Safari.
From my point of view, MS Edge is a secure browser, where other Chromium-forks often fail to meet the end criterias. Also happens to be on Apple, yay
