Just keep retrying, eventually the counter will catch up; or set it directly, under Platform/Counters.
Also, set the instance prefix of each environment to the first letter of the env, 'D' for Dev, etc. This will make it so when users and untrained consultants don't name their objects and then export them across env's they won't collide.
Is the error always referring to the same folder name i.e. - Folder322 or it's different each time.
The error tells us that there is a folder with that name already hence it's not able to create one again.
Also, can you share the steps you are taking to create the new folder.
I set the counter directly under Platform/Counter. It worked.
I will try to set instance prefix as well.