I gave away my Reface DX after I figured out that the non-tactile capacitative touch buttons would trigger randomly when exposed to sunlight while I played it in the park.
You might have had a defective one.
I played mine in every possible setting (walking the streets, in the forest, on a mountain top, in the desert, indoors, outdoors, at night, during the day, etc), and never had that issue. (FWIW I applied all firmware updates when they came out).
I did have other issues though:
— once in a blue moon, it'd factory reset itself on startup while running on batteries (a gentle reminder to back up your patches). I didn't have that issue after switching to powering off a power bank with a USB-to-12v adapter (with USB-C supporting 12V natively, that's just a cable).
— sometimes, F and Bflat would stop responding in all octaves. A gentle whack would fix that. Taking it apart and making sure all the connections are tight seems to have fixed it for good.
What I'm getting at is that there absolutely were some QC issues with an otherwise nearly indestructible instrument (between all the drops and two Burning Man trips, boy did that thing take a beating).
Might be worth giving it another go if that's the only problem.
https://www.planetanalog.com/force-sensing-eliminates-false-.... (See the bit on the VCNL3030X01 sensor in the middle. I tried to text fragment link, but HN seems to strip that off)