Thanks for the checks. I can also confirm that kernel 5.15 with current updates (date: 2022-06-16) is causing havoc. Testing with manjaro VM in manjaro virtual box Host system. Same issue as others here reported - vm becomes unusable after some minutes, sometimes even on boot
Switching forward to kernel 5.18 in the host system solved the issue for now.
… waiting for a 5.15 fix and will keep on testing as well in the next days.
P.S.: Manjaro VM (KDE, Kernel 5.15, booting via btrfs on a luks encrypted VMdrive) works flawless, I retested installation procedure multiple times. Each Install roundtrip took ~5 minutes. Tested different installer options regarding SWAP, btrfs and encryption during installation.
… this works (tested ~6 combinations) as designed every time … when virtualbox is working correctly