First Officer reported autobrake; radar altimeter; and thrust lever malfunctions during final approach and landing at PHX. The flight crew continued and landed safely.

Narrative

Possible 5G event. On arrival in the terminal area; the crew noticed the autobrakes disarmed twice after arming. I was the PF (Pilot Flying). The PM (Pilot Monitoring) ran the procedure and we set manual braking for the arrival. At 2500 ft. MSL and again at 900 ft.; the CA's (Captain) radar altimeter become inoperative with a red flag. This was noticed by the PM and on his side; CA; only. He did not tell the PF. In the flare I noticed a resistance to pitching up. It almost felt like the autopilot was still engaged. I overcame the resistance to set the landing attitude. Additionally; the AT (Autothrottles) did not go to idle at 27 ft. as normal. I manually closed the thrust levers prior to touchdown. The spoilers worked normally. As the nose wheel came in contact with the runway; the thrust levers started to move forward. I held them back and disarmed the AT. This delayed my engaging the thrust reversers a few seconds. The aircraft was stopped without incident. The Captain wrote up the radio altimeter at the gate.We did not recognize a possible 5G event might be occurring. The CA did not communicate his radio altimeter failure to the FO (First Officer) / PF. If someone gets a red flag on their side; alert the other pilot. The approach should have been flown with the AT off both for the radio altimeter failure and the current 5G policy.