...
You may encounter this error when performing read/update/write operations to a Google sheet from a form/flow. The Google API can never be a replacement for a database in terms of reliability. It will not scale because it is a remote service and There are no SLAs associated with free google accounts. makes multiple http calls to that service the Google API with no guaranteed SLA. As the load increases, the chances that it the Google service might fail icnreasesincreases. If you encounter the 'internal server error', the only thing to do is to try again later.
...