I bought a Logitech MX Ergo a couple of years back and genuinely love it for many of the reasons other trackballs users cite in this thread - but I have noticed in the last few months that my thumb joint will get 'stuck' and makes a click when I unstick it. Definitely related to the MX Ergo and the thumb navigation like you say. I'm an older gentleman which likely contributes.

So might be tempted by an all finger alternative - at the moment I'm attempting to up my use of a terminal window manager to minimise pointer use