I have a design that has been migrated across several revisions of Vivado and is currently under Vivado 2019.1. The design incudes several IP blocks packaged into core container (.xcix) files. I do not wish to update a couple of these cores to 2019.1 and have left these in the "locked" state. Even though they are locked, Vivado appears to modify these files every time I open the project. This is particularly annoying since I use git for version control and these large files are continually being touched by the toolset even though nothing has really changed. Is there a way to force Vivado to leave these files alone?