Replying to
@shuppy@fedi.shuppy.org
but if you wanna do that after you migrate (or in a new repo), then update the issue_index table where the group_id matches your repository id (in the DB) to set max_value as one number less from what you want your starting issue index to be
(idk if you can do this in the FE. see 3rd and 4th screenshot for code. forgejo code is the same)

