In all my years of working on 1911's I've never had a sear spring lose it's tension.
However I'm not saying that can't happen.
If Caspian cut the frame for the grip safety sometimes the radius cut they do is very generous, thus allowing the grip safety a lot of wobble.
This along with other things may be the problem.
Here's something else to check.
The slot in the grip frame that the tab on the sear spring fits into to hold it in place may be to large allowing the sear spring to walk to the left.
If this is the case stake the slot in the frame on the left side of the tab.
Also check to make sure the tab on the sear spring is not sheared off the spring.
Best Regards
Bob Hunter
www.huntercustoms.com