I just resolved this issue with Elektron. I sent them this message and just received replacement buttons for my Digitakt and Digitone for very little cost. I agree with others, they need to trash this material and replace it with something that doesnt degrade. The coating on my Arturia minibrute was even worse, if you can believe it. AIAIAI TMA-2’s - the list goes on, so many popular products use this awful coating.
" Hi, I’ve had my Digitakt and Digitone since Jan 31 2020 (just under 3 years). The rubber coating on the buttons has gotten very tacky/sticky. They had gotten this way on their own slowly over time, and the problem became worse when I tried using basic household cleaning products to wipe them down.
I have read posts on the Elektronauts forums about others having this problem. Some have said you can completely strip the rubber off using isopropyl alcohol, but I don’t want to do this especially for the colored buttons. What official solutions are there from Elektron? Since I am under 3 year warranty, am I able to get a set of replacement buttons for both Digitakt and Digitone?
I have proof of purchase of these from 2020. I didn’t register my products on the website until just now, but I did buy them less than 3 years ago."
(I then included my serial numbers)
They responded with a draft order for the discounted buttons ready to go. Hope that works for you too.