Upload Issue

It varies based on your approval and sales history. 

If you’re brand-new to Stock, your weekly submission limit is around 50 assets.

But it will gradually increase as gain more experience.

Upload limits are different for every contributor. When you’ve reached your limit, your submit button will be greyed out and you will need to wait a few days (probably typically a week) to continue submitting. You can upload as many assets to the Review tab as you wish.

Adobe Stock does not publicly disclose specific upload limits.
The number of uploads allowed changes based on your track record as a contributor.
Beginners are limited to a smaller number of submissions.