B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 522
Troubleshooting; Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Flight Crew FLC Overrode Automation
Aircraft
During training; for the 737-MAX there was no mention that using the Altitude Intervention (ALT INTV) button would change the FMC altitude. However; when we entered a lower altitude from cruise altitude and selected the ALT INTV button; the MCP altitude was entered into the FMC. When we received a new lower altitude and entered it in the MCP and with VNAV selected the aircraft did not start a descent like previous NG aircraft.We noticed that the FMC had a new cruise altitude that we had not entered through the FMC. (The altitude had automatically been entered from the MCP.) We selected the ALT INTV button to allow the aircraft to descend again. This happened two or three times. This safety issue was unexpected and could lead to an altitude violation and safety hazard. 737-MAX FRM (Fault Reporting Manual) 4.1.3 item 10 Altitude Intervention switch: under 'push-(during VNAV cruise)' states: 'Lower FMC cruise altitude cannot be entered using ALT INTV switch.'  Our aircraft DID reset the FMC altitude with the ALT INTV switch.
Captain reported procedural issues with the FMS on the 737-MAX in reference to descent capabilities.