you did a hard reset in such a short time ...?

(looking at the time stamps of your posts)
you are sure the supercapacitor of the sensor array was completely discharged ??
By experience this tends to take longer ...
But be it as you say ...
If a proper and complete hard reset didn't do the job, then possibly the T/RH sensor is either defective or loose (virbations, wind ...). If you are still inside the warranty period, contact Ambient for replacement; outside the warranty I would contact Ecowitt (the manufacturer) via support@ecowitt.com and ask if they can provide a replacement sensor or kit.
If you have a newer hardware revision model of the array, the sensor can be exchanged by "plug-and-play".
Outside warranty I would first open/remove the radiation shield (should be two screws) and check if the connector of the T/RH sensor cable is sitting tightly and see if pressing it tightly into its socket will create a change.
Otherwise I'd contact first Ambient and if not successful Ecowitt. This part of the array is still seller independent and is not affected by the Ambient "firmware lock". So if Ambient cannot and Ecowitt can provide a solution, it should work.