Hi amgravs2,
Could you show me more details to help reproduce this issue on my side?
I assume that your app is based on an Excel table. You have a submit button to submit data to the Excel table.
I am not sure with this “PowerApps changes the column back to "General"”, could you show me a screenshot about it?
To test this issue, I create an app based on Excel table which is stored on Dropbox. I can write data back to the data from PowerApps without issues.
About the Excel table, I have a number column, and I configure the number column’s data type to “Number”.
Then auto create an app based on this table, try to save data to the table, succeed. Then I go to the Excel table to check the data type, it is Number, which doesn’t change back to “General” as you mentioned.

Please feel free correct me if my reproduce step is different with yours. And it would be great if you could provide more details about this issue.
Best regards,
Mabel Mao