Crown repeatedly not fitting

I’ve been seeing a dentist since early this year and have experienced some things that seem troubling, but I wanted to get some outside opinions to see if this seems abnormal or if I just don’t really understand the normal processes for getting a crown.

I got a root canal from an endodontist earlier this year which required a crown to be put on the tooth afterward. I went to my dentist afterward to get scanned for the crown. When I went back to get the crown put in, the crown was too tall. The dentist said that the lab told him the crown couldn’t be shortened anymore because it would make the material more brittle and have a much higher likelihood of breaking. He recommended I go back to the endodontist to get a gingivectomy so more of the tooth could be exposed since there apparently wasn’t a lot of tooth left after the root canal was performed, and that would help the crown to fit better. I got the gingivectomy done and went back to get scanned again for the crown. When I went back to the dentist to get this second crown put in, it was still too tall, and he was unable to make it shorter in his office. He told me my teeth must have shifted since they scanned me for the second crown (which was about two months ago, scheduling has been a whole other issue) and that’s why this one didn’t fit. They scanned me yet again to get a new crown, so this will be the third crown they are trying. Is it normal to have to have multiple crowns made to get the right fit? I’ve been pretty frustrated that I have to keep going back since I got the root canal back in March and it doesn’t feel like it should take this many times to get it right, but I’ve never had a crown before so I don’t really know what’s typical.

I’ve been planning to get a new dentist anyway since there have been a few other issues with this one, but I’ve already paid him for the crown so I wanted to at least get the crown put on before I switched to someone else.

I would appreciate any input or advice you may have about this. Thank you in advance!