Well, go to your cloudflare, and pause it ! I hope you know how to pause it?
Pause it then, go to your caching, and purge everything.
Wait some minutes and re-try.
If it was me, i could have combine that by also going to /public_html/assets and delete all css, all js , all map and .json
Also could have deleted files in storage/cache
storage/formatter
storage/less
storage/views
Then clear cache again with the php flarum cache: clear
