This has been occurring with me for a while, but I seem to only notice it on old files (created before 2023 and upconverted).
Unfortunately, this is our main workflow, updating shows each year without starting from scratch - especially if the scenic hasn't changed.
Curious if there's any fix planned for this.
Knowing it's been an issue forever, I try to edit the Instrument Summary only once a day or at the end of the project before publishing, so I can go get some coffee and wait 10 minutes for the dialog to open.