Conversion of 2018-08-04 23:44:59 from user format d/m/Y h:ia failed

I tried this fix but now get a slightly different error:

convert: Conversion of 19/05/2021 15:46 from Y-m-d H:i:s to d/m/Y H:i failed

followed immediately by:

fromUser: Conversion of from user format d/m/Y H:i failed

Any idea what needs changed here to resolve?