Downgrade is a fast solution.
It is. But won’t get to the bottom of your issue.
People can’t be a beta tester with their sites in production.
Absolutely true. But you’re assuming this is due to a bug and not because of planned behaviour in the release – you may not find any future release of WordPress will resolve the problems you’re seeing.
Did you not experience the problems when you tested the Beta or R1 before yesterday?
A lot of problems with 5.5, java slider and adwords sidebar don’t show.
I’ve had a quick look and can’t find “java slider” or “adwords sidebar” in the plugins directory – otherwise I would have taken a look at these. Both sound as if they may be reliant on JQuery – a change was made to this in 5.5, which may cause some older plugins to break. If you’ve not done so already, check the plugins’ forum to see what other people are saying it. Also see if the developer has released a new version that may resolve it.