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.
Excuse my typos and sometimes awful grammar. My fingers work faster than my brain does :-P
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