Hi,
This seems to be just a Chrome bug with discourse, related to the size estimation for data stored in local storage.
The discourse team already has reports for this and are actively working to mitigate the issue.
Let me point you to the respective discourse thread:
Since this will be fixed for the balena forums once discourse releases a fix, I think that the above thread is the best place to keep track of this issue.
Kind regards,
Thodoris