Surely a bug.
In a task to change the values in column, [_thisrow_before] operators to reach out the previous value before the data change can NOT be used in those action, as [_thisrow_before] is sort of ‘short-live’. On the moment when the record value is change, this special syntac will get the previous value from the column. Hence, this operator can not be used in Action. We can confirm this when we create the action, and error is shown to alter us.
Ater we see this error when we are bulding action, but keep moving by hitting save, surprisingly App is saved without further error. But after that we go back to the action and re-open the expression editor, thne ofc we see the same error. All in all, we are curently able to save WITH error on this action setting. Dispite this error, action is runnable, but this operator is actually returning [_thisrow_after] value.
This second one may have share the same root cause as the first one.
We create a task from this errornous action (error with this [_thisrow_before] syntax, we are able to generate a bot. BOT is not throwing any error at all on this occasion, which seems to be another bug, whle we see error when we interact with Actoin from Behavior tab, instead of Automation pane.
Yes, this bot is runnable. Same story. BOT return the thisrow_after value, while we errorly push thisrow_before operator into the action.