I am using Google Sheets API v4 to read a spreadsheet content in my project. It has worked just fine for a few months, but recently I started to get a PERMISSION_DENIED error while reading some, but not all of them.
All the sheets worked properly before, but now some of them can't be read (resulting in PERMISSION_DENIED error) while the other ones still work fine. Also when I create a new sheet it does NOT work.
All the sheets are available for viewing for anyone at the web, I did not change the API key I am using, the sheet owner did not change, some sheets have not even been modified for weeks. Long story short: I did not change anything (that I am aware of) that could impact reading the sheets but yet some of sheets suddenly stopped working.
Has anything changed recently in how Google Sheets API works? Or am I missing something else?
EDIT:
A few hours passed by and some sheets that previously did not work now work and some that did work now don't. The sheets have not been modified in meantime.
May this be caused by reaching any usage limit? I don't get RESOURCE_EXHAUSTED message though. It's PERMISSION_DENIED in each case.