I’m not familiar with using the glide api’s, but it appears that you are passing the date/time as a string. If possible, you may need to pass it in a date format. Sorry, can’t really help much beyond that.
I use integromat mostly to write back to Glide and I don’t have this problem with time stamps. I format time as YYYY-MM-DD HH:mm always too. Also have you tried with another column first, in case it’s getting confused when it writes in a row… otherwise not sure!
In my experience, any time you see timestamps appearing as strings in the Google Sheet, it inevitably means that the associated column in Glide isn’t correctly configured as a Datetime type.
So that’s the first thing I would check. Edit the column in the GDE and ensure that it’s correctly set as a datetime type.
Note that just eyeballing the column header is not good enough. Sometimes you’ll see the calendar icon next to the column name that indicates a datetime type, but when you edit the column, you’ll find that the column has a type of ‘None’. This only ever happens if the column was originally created in the Google Sheet and then synced to Glide. It would never happen if the column was created in the GDE.