1) Not all mounting plates are created the same. Since 2019, we have used Dynacore Vmount and Gold Mount plates as these seem to have a high level of compatibility with all sorts of packs. We previously sourced IDX plates, but these seemed to be a bit finicky around mounting off-brand batteries well.
2) Not all batteries are the same that claim VMount compatibility. There are a few issues that arise. Mechanically, the battery might not seat well or lock consistently. Mechanically, the pins might not be centered on the right axis to make secure contact. Electrically, the pins might have low-quality plating the wears quickly and can result in intermittent connections.
Our recommendation is to test your battery pack out to ensure there's a mechanically solid connection that latches in securely and keeps consistent electrical contact when wiggled on the mount.