The column's value won't revert on its own, which either means someone is performing a restore on the database (which would revert everything) or someone or something is running an UPDATE, or DELETE and INSERT, statement that sets the value to a value that is the same as it was before.

There's a few options you could consider, such as setting up a trigger, an extended event or a trace. Do you also perform any ETL processes on the table? Perhaps that process is overwriting the value.