Just to clarify — as mentioned in the document I shared above, even if you didn’t move the file to the Trash yourself, anyone with “can edit” access to the file’s parent project can move it to the Trash.
So, if a similar situation happens again, the first thing you can try is to check the Trash of the teams you have access to. Each team has its own Trash, so please switch between teams in your file browser’s sidebar and check there.