donna, just a bit of advice, wear a baseball cap when you shoot and leave the boy magnet shirts at home.
My daughter was shooting her Para Ord and a empty hit the divider at the range and a piece of brass dropped down her shirt front. Because she was hoping to see a friends son at that range, she had worn what she calls a boy magnet shirt, ( I have told her I do not care for those shirts but she choses not to listen to me) anyway for a good while she had TZZ 88 branded on some tender tissue.
As far as that issue happening,
Change a recoil spring.
Remove the slide and look at the ejector. Peened or worn might warrant a replacement. Adding a longer one can help but may make other issues show up.
Remove and clean the rim groove on the extractor. something gets built up in there and you can have troubles too. If you have another 1911 you can try and use it's extractor to see if it hold the case differently and fixes the problem.
if you can get dummy rounds try cycling the gun real slow and watching the action of the case as it leaves the barrel. Doing this without the recoil spring sometimes lets you see what is going on and see something that is catching or rubbing.
ejectors are cheap too and you can buy a surplus one from CDNN for 5 bucks and a colt officer aka extended for 10 bucks and a colt series 70 extractor for 15 bucks. this a few different wieghts of recoils springs are a good thing to have anyway for parts. just try and see, a lot of the fun is seeing if you can fix it yourself. that said, never try to remove any metal (file, sand, or dremel) from any part you are not willing to replace.
It is onething to grind a bit of metal off a 9 dollar ejector to get the right angle than to try to open a ejection port in a slide. experiment on the new parts too. then you have the originals as guides.