I am on the free plan so can't file a ticket on this issue - looks like a bug that many others have filed. Sometimes a workaround, most often the reply from Mironeers is that your 3-Board limit is for the entire team, not per-person on the team.

Context:

I have 3 Private Boards in my Miro.

I can edit 2 out of 3.

I am the only team member.

All boards are "No Space" because of Free plan (according to the Upsell icon).

None are shared.

none are marked read-only.

I was a member on somebody else's Free plan, but left the team to see if that would resolve the issue. It did not. 

Chrome

MacBook Air M1

Miro app for Mac also fails

iPhone app also fails

I can fully edit 2 out of my 3 free Boards. However, on the 3rd Board, starting about a month ago, I can no longer make any edits on my main board. Example of what I can't do:

-- I click the Frame tool and select the area where I want the Frame to go. The Frame briefly appears on the board but then vanishes.

-- Try to paste in an image - again, briefly appears then disappears off the Board without being added.

-- try to drop a new sticky on the board or copy-paste a sticky, same thing

-- try to delete a sticky, intermittently the sticky will vanish, but then reappears, sticky not deleted.