Lightroom Constantly Hopping Screens

I use a MacBook with an external screen, configured as below.

Lightroom will constantly hop between screens. Sometimes spontaneously, often when I switch between apps. This has been happening for a year or two, sometimes more so, sometimes less, across several LR and macOS updates, and a new MacBook (all apps reinstalled fresh, not copied across), so it's not some quirk of my install.

If I'm switching between apps frequently, it's usually because LR is part of another task, and having to constantly relocate LR to the large screen is very irritating.

LR Build: 202306052221-b70c0975

Hardware Overview:

  Model Name: MacBook Pro

  Model Identifier: MacBookPro18,4

  Model Number: Z15H000UBX/A

  Chip: Apple M1 Max

  Total Number of Cores: 10 (8 performance and 2 efficiency)

  Memory: 64 GB

  System Firmware Version: 8422.121.1

  OS Loader Version: 8422.121.1

System Software Overview:

  System Version: macOS 13.4.1 (c) (22F770820d)

  Kernel Version: Darwin 22.5.0

  Boot Volume: Macintosh HD

  Boot Mode: Normal

  Secure Virtual Memory: Enabled

  System Integrity Protection: Enabled