whats your method to warm up bing ads?

Maybe something has changed on google's side and if all four accounts got blocked within hours then you should check the suspension reason before trying the same setup again.

Bing had some major policy changes in the past 6 months, the are monitor everything much more carefully. In terms of warm up I do what I always did with a very generic niche but I am linking to my own site. so for example if my niche is flowers (like in your screenshot) I will create a flower store page on my domain and redirect the users.

I think the most important thing to remember is its very sensitive to changes, so one the warm up phase is completed I will upload my campaign, ag, kw and ads and I will not make any other changes, not even bids. from my experience this is the thing that prove to be the most useful, just make sure your initial upload in final.

Yes, I have seen cases where verified accounts still face restrictions and review the policy notifications and appeal if the block seems incorrect instead of repeating the same setup.

I hate Bing why not go with google ads of fb

I think it is worth contacting google support to understand the exact restriction reason because changing the warm-up website alone may not solve the problem.

I think, this could be a recent enforcement change but it's hard to say without knowing the suspension reason. What message are you getting when the accounts are blocked?