At the end of 2018 Microsoft implemented autosave in Office365. I experienced a few problems with older workflows that were set to “Start workflow automatically when an item is created”. The problem is that, due to autosave, documents were being “created” before metadata columns had their information populated.
This resulted in the workflows initiating and experiencing a coercion failure [Coercion Failed: Unable to transform the input lookup data into the requested type] because the workflow was trying to use a field that wasn’t yet populated.
A good mitigation for this is to add the “Wait for” command at the start of a workflow. Example “Wait for fieldname to be not empty”.