We migrated from
https://example.com.It 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 https://example.org/
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.