Orion XS #67 BMS connection lost

Have new install with Cerbo GX, Lynx Smart BMS 500, and an Orion XS 50 (amongst other components and all have latest firmware). Orion is connected to Cerbo via VE Direct and BMS is connected via VE.Can. I want Orion to charge a start battery from lithium house bank. Under the Orion Device settings on the Cerbo I’m setting it to “Charge another battery from the main battery”. All seems fine for a couple minutes but get error “#67 BMS connection lost”. Both devices are still visible via Cerbo so connection seems ok. Have tried resetting Orion and reconfiguring but got same result.