Numerous media player bugs were introduced almost a year ago in the 8.0 release.
Tesla quickly fixed one major user interface flaw by restoring the first letter scroll bar for media player lists - but left other user interface mistakes in there, such as losing the XM station slider.
There are also multiple obvious bugs that have yet to be fixed. For those of us who are XM subscribers, the XM radio is almost unusable because of the combination of the lost XM station slider coupled with the inability of the software to load and retain the channel information & station list.
The media player turns on periodically by itself. It loses the currently playing USB song when changing sources. The shuffle mode for USB songs plays songs in the same "random" order every time.
These are all known problems.
Musk mentioned that 8.1 was supposed to contain a number of media player improvements and fixes - originally expected to be released in December. But it's taken them much longer to get the AP2 software up to AP1 capabilities - so it looks like everything that was non-AP (and non-Model 3) has slipped. And even though we saw 8.1 released a few months ago, it didn't contain the media player fixes, or the promised kernel update & improved browser.
Surely Tesla will fix these problems - and all we can do is continue to report the issues - and be patient for them to get the software released.