Hello!
I told about your issue to the appsheet support team and they kindly asked you to raise a case with them in order to investigate further.
Please, find a part of the answer I received from appsheet support team where they asked for your cooperation in this subject:
"Our dedicated team has thoroughly reviewed your conversation on https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/error-message-quot-Unable-to-add-row-to-table-Invalid-request/m-p/696002.
Their analysis indicates that it would be beneficial if you could kindly request another user to raise a case with us. This will enable us to conduct a more comprehensive investigation and provide you with the necessary assistance."
Thank you!
Regards!
Ruxandra