Fringer EF-FX Pro II Lock-Up Issues

I have a Fringer EF-FX Pro II adapter that I've purchased directly from Fringer when they were first available about 18 months ago. I've experienced intermittent problems with it since then. About 20-25% of the time, when I press the shutter to focus, the green focus lamp will light up and stay lit up but the camera will lock up and I'm unable to do anything else like change the film simulation mode. I will have to shut off the camera for the green light to turn off. It started happening with my X-H1 shortly after purchasing the adapter. At the time, I wasn’t sure if it was the camera or not. I recently purchased an X-S10 and the same behaviour is happening on this camera as well. I've noticed that I can change the focus point on the X-S10 while the focus lamp is green but that's about all I can do. It's happening with my EF-S 35/2.8 macro and my EF 50/1.8 STM but I need to confirm whether it is occurring with my EF 100/2.8 L macro or not.

I've contacted Fringer about it and they have asked me to try to determine the exact conditions under which it is happening so that they can try to duplicate the problem. BTW, Fringer support is consistently impressive. I sent them an email about it yesterday and they had responded twice overnight even though this is Lunar New Year's in China. They've been very responsive in my previous communications with them as well.

Anyway, I'm interested in finding out if anyone has also experienced the same issue with this model of Fringer adapter (they have a few different variants) and, if so, I like to know the specific conditions under which it has occurred. My goal is to share this information with Fringer along with the further details about my own situation. so that they can problem solve, and hopefully, issue a firmware fix.