Tacx Flux S unable to hold resistance on climbs

I am currently using a Tacx Flux S for Zwifting, which is connected to my iPad Air via Bluetooth. I have been experiencing a recurring problem where the trainer is unable to maintain consistent resistance while climbing. The resistance fluctuates between the actual watts I am putting in and sub-50 watts, occurring every alternate second or so.

I have attached a recording of the companion app and power graph on Garmin for reference (link provided below). While riding on flat terrain, the resistance is generally smooth, but as soon as I start climbing or sprinting, the issue resurfaces. This problem has made it challenging for me to go full throttle during intense cycling sessions, severely impacting my overall cycling experience.

I reached out to Garmin a few months back, and they replaced my trainer, but the replacement unit is also facing the same issue. I am unsure of what could be causing this problem, and I am wondering if anyone else has faced a similar issue. Would trying the trainer on my laptop with an ANT+ receiver be a viable solution?

Recording of the companion app: https://imgur.com/a/FzmG90L

Power graph on Garmin: https://i.imgur.com/hPEnK2l.png