Thank you @philm! I updated and now I have a working anbox again.
The anbox update came up, thanks for your work!
If someone knows about how to add the other programs like Siglo and the Add/Remove Software App would be amazing 
BUG REPORT: I updated from Beta 8 using the testing branch.
Sometimes the phone freezes. When playing YouTube and some additional causes I don’t know how to reproduce. What means frozen? I can’t see anything the display is black, when I turn the display off and on again it’s still black (with backlight) but the audio is playing as nothing were happening.
Additionally I got problems with Bluetooth. When turned on it is show as on in the bar above, but in the setting (where the Bluetooth devices shall be listed), I got a text, that it is still states that Bluetooth is still turned off. This can only be changed with fully turning the phone off and on again. Than I can see all the found devices. After connected to a Bluetooth headset, the audio buffering often (playing ~2 sec, buffering 2 secs). The display freezes similar to above.
Two smaller problems. Often the display is using a wider space than the display width (therefore some amount of the display is cut off). When playing audio (in the podcast app), the playback stops after a while and only continues when pushing the on/off button of the phone.
Wishlist: Add more languages. Still can’t read the characters for some (like Chinese).