Air carrier flight crew reported a malfunction with the Radio Altimeter during approach to land at CLT airport.

Narrative

I was acting as PIC on flight Aircraft X from ZZZ1 to CLT. The following occurred on DATE at around XA:10 Zulu. We were established on the final for [Runway] 18R into CLT. Between 3000 and 400 ft. we received 3 EFIS (Electronic Flight Instrument System). COMP MON RA caution messages. They appeared and disappeared in less than 2 seconds. I noticed that during the caution messages the captains side RA was erratic. My First Officer was flying and the autopilot/flight control computer was coupled to his side. During the event; his RA did not show any abnormalities. Because he was flying with no abnormalities on his side and the weather being VMC with light winds we both decided we could safely continue the approach.At 400 feet I pushed the FDR (Flight Data Recorder) event button but did not see an associated green or white message. We landed as normal and when we arrived to the gate I wrote up the discrepancy in the maintenance logbook and contacted maintenance control. I also contacted CLT ground on 121.9 to give them the information that I had for the incident. I also submitted an ACARS report to dispatch with the details of the event.Pilot should maintain situational awareness with onboard systems during the approach phase. Emphasis should be placed on pushing and holding the FDR event button. Most likely a faulty radio altimeter system on the captains side. In my personal opinion I don't believe it was associated with a 5G disturbance.