This issue originates from this TRF thread: https://www.rocketryforum.com/threads/issues-with-openrocket-simulations-after-upgrade.183055/

The Override tab looks like this:

For a Stage, the standard way to override would be to
a) Override the mass and check "Override all subcomponents" (unchecked by default!)
b) Override the CG and do not check "Override all subcomponents"

This is fundamentally confusing, and the dialog itself gives no guidance. What does it mean to override a stage mass and not override subcomponents? What does it mean to overide stage CP and override subcomponents?

As shown in the referenced TRF thread, neglecting to check the subcomponents override for mass can have a disastrous effect on the flight sim, and there is no warning of any kind given.

I'm not sure what the solution is but this must be addressed next release.

There is also a question of whether files created with 15.03 are opening into 22.02; I haven't been able to answer that yet.