This is a common problem that I've seen many times.
It's due to incorrect reassembly after a strip down.
You've accidentally "fixed" it by twiddling with the sear, but it'll come back.
If you're not competent then give it to a gunsmith as lives can be in danger when triggers are adjusted by people without the correct knowledge.
That said, your problem was that the sear was not fully engaged in the bottom of the housing but now is, due to your attempts to adjust it. To double check this, pull the trigger completely and push down on the sear with an appropriate tool (nylon rod). If you look at how the sear is retained you'll see its by a stainless starlock. You should renew this, but if you decide not too, then all you need to do now is seat it fully against the sear (there's a you tube video for this). You'll find its a few millimetres up the pin from where it was originally incorrectly seated. This will stop the sear sliding back to where it was and reintroducing your creep problem.
Like I said earlier if you're not competent then get someone else to do it.
Knockedover on here or indeed chris cundey or pete dutton are all excellent and any of those guys will do the job properly.
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