Change of address tool couldn’t fetch the page error

We migrated from to seems we have done all requirements mentioned here for using search console change of address tool but now it has passed 4 days from our migration and still every time I try to use the change of address tool after pressing ‘VALIDATE & UPDATE’ button, There is validation failed pop up.

The error is:

Couldn’t fetch the page

Using the inspect url I see no problem with both urls. I also submitted an index request for both versions. All urls are redirected with 301 status code.