Linktoform Bug?

[SKETCHwade]

Hello,
I think I’ve come across a bug.
I am using a time column that is not editable has no formula or initial value.
I am using an action and linktoform to determine the columns value.
Link to form is working correctly as it shows the form with the correct column and value.
When this form is saved the data is not uploaded to the sheet though.

This is the result of the action:

The Start time is clearly 1:32 PM which is correct.

Hitting save I see this data in the spreadsheet:

The start time was not uploaded.