That PR made Anki use system certificates, so yes, reverting that will probably solve @Headless’s issue, but will re-introduce the issues solved by the PR. The PR actually introduced a common issue for Windows users with fresh installations/missing updates and has been a source of a lot of error reports on the AnkiHub forums, but I’ve never seen this particular error before. I suspect something is wrong in the OP’s system certificates as you suggested.
SSL issues will probably be fixed when we work on this: Consider using Truststore to expose system certificate stores · Issue #3793 · ankitects/anki · GitHub