I have a sheet that uses a formula to join the text from 3 columns into one so it will display easily on a dashboard. This has been in use for almost two years.
Suddenly, it has been giving #Invalid Operation errors on the columns that it is joining. The fix is to open the sheet and edit any cell—related to the columns involved or not—and save it. That fixes the sheet for a while. It eventually reverts back to the error message.
Any ideas why this might be happening? It has automations that run every hour and either check or uncheck a box in a column unrelated to the ones causing the error. I haven’t been able to confirm if the automation coincides with the error showing up.