B737 MAX 9 First Officer reported an erroneous GPWS alert related to landing gear during final approach. Flight crew performed a go-around and landed safely.

Narrative

Uneventful flight up until a XXL approach into ZZZ in visual conditions in a MAX 9 aircraft. Landing checklist was complete; and we were on a stable approach with autopilot (AP) off and auto throttles (A/T) off. Almost immediately following '500' callout on approach; I was replying 'stable' when a 'too low; gear' aural warning sounded along with red PULL UP visual annunciation displayed on the Primary Flight Display (PFD). This brought my attention to the gear indications; where I saw 3 green- down and locked. I announced I was going around; and we performed an uneventful go around procedure that concluded with a clean aircraft and after takeoff checklist complete. We took delay vectors from Approach Control to work the issue- I flew and talked while Captain started checking for any associated QRH procedures. The only Flight Manual (FM) reference we found was if you hear 'too low; gear'; execute missed approach which was already completed. We discussed the possibility of a faulty sensor connected to the GPWS warning we received; as we both agreed that we saw gear down and locked at the time of the warning. Captain contacted Dispatch/Maintenance Control. We confirmed with Maintenance Control that we had no other abnormal indications. We selected gear down again while on delay vectors; and confirmed that we had 3 green indications in the standard position as well as on the aft overhead panel. We were unable to find any associated QRH procedure for this instance; and decided to not inhibit any GPWS associated switches; as we had no other indications of faulty function. Captain briefed the Flight Attendants (FAs) and made a PA to passengers. We decided to [request priority handling] with ATC to have Crash Fire Rescue (CFR) on standby for our landing and requested vectors ILS XXR. We configured early on this approach to guarantee we were showing 3 green on both gear indications. An uneventful approach and landing was conducted; and the aural/visual warning DID NOT occur on this second and final approach. An uneventful normal landing occurred. Upon exiting the runway; we informed ATC of no further assistance required from CFR and taxied to the gate. ELB report created for the issue; local Maintenance was waiting for us upon arrival.