I tried renaming .config and .local, and deleting all budgie-welcome results from a search in my home folder.
The only computer that had the issue was my main desktop so after a few hours decided to cut the losses, delete and recreate my user, only re importing a very limited amount of .dot files. And issue resolved.
Sorry i could not provide more accurate resolution, but at least we learned it is somewhat linked to user account.
… try .local as well
This folder looks suspicious … .local/share/webkitgtk - try renaming/deleting that.
Renaming only .local/share/webkitgtk did not help. But renaming the whole .local folder did it!
Hmm … so it must be one of the subfolders … needs a bit of an investigation to find which one.
It would be very beneficial to find the exact folder or file. I will try to replicate my podt install steps on a virtual machine, see if i can get to the same problem.
It’s working! I’ve changed nothing, so it should be ‘repaired’ during an update…
Hello, I am new here and also have something to contribute immediately.
I had exactly the same problem. budgie-welcome has a white page after install (SNAP) and start.
I experimented for hours and found out that the following file was to blame: ~/.local/share/mime/mime.cache. I deleted them and now budgie-welcome starts as it should!
Greetings!
Ubuntu Budgie 22.04 LTS
Hello @DPoi and welcome to our community.
Thank you so much for your contribution. It was a good catch!
Thanks a lot, great that you’ve found it. After updating to 22.04 it was blank again - but now it works again!
Hello, I am glad that I could help! I need yes also sometimes help. Then I have created a small balance. 
Thanks and greeting!