New Bug Encountered: Add new row button dissapears

Hi everyone I’m facing the followin issue, as I was developing a new app the button to add a new row suddenly disappears as shown in the following screenshots

I’m using chrome 76.0.3809.100(Official Build) and Windows 10 version 1903. I’m currently in free developing mode but previously I have previously developed other apps in free mode and I did not have any similar issues. Any ideas on what could be going on?

Each screenshot shows a different dataset. Different datasets may have different permissions for adding rows, or their Add actions may have different display logic.

Sorry I should have uploaded the same dataset, in this screenshot the add button is not shown, I checked and they have the same display logic

Thanks in advance!

It appears the General table or slice does not allow adds.