To climb K2, I always recommend the participant first have a thorough psychiatric exam. Oh, wait! Just kidding!!
But seriously, you’re wise to take winter travel and avalanche safety seriously. As for a beacon, I think any of the three most widely used onesthe Tracker DTS ($300), the somewhat venerable Ortovox F1 Focus ($250), or the newer Ortovox M2 ($300) work fine. I am not familiar with the problems that you mention, but I do know that the current version of the Tracker DTS uses “send” mode as default, so perhaps that’s a retrofit aimed at fixing the issue you cite. Certainly, the digital technology used by the Tracker is designed for cold-weather use, so I don’t believe that’s a concern. Same for the M2, which is more “digital” than the older F1.
In any event, all that really matters with an avalanche beacon is that you: A) know exactly how to make use of one quickly, and B) take steps to ensure you never have to rely on it. Before any outing, you and your partners should review the use of one of the receivers, and then take turns burying one out of sight and having party members track it down. Also, carefully review recent weather reports and the impact this may have on avalanche conditions. Then, dig a snow pit for an on-the-spot assessment of the snow density and whether local conditions may cause the snow to slide.
Good luck!