There are two separate issues here – the missing letters and the rendering issues (like in the “A Wizard, A True Star” album name above).
The missing letters means that the GPU is running low on resources. We’re aware of this issue, but it is a performance problem that tends to occur on under-powered devices or on devices that are running low on video memory. This is almost always resolved with a reboot.
To be clear, we’re not ignoring this and we are always working to improve Roon’s performance, but there is a lot of variation in the Android ecosystem, which makes it extremely hard for us to guarantee that every device will always have enough video memory to run Roon.
The rendering issue is not a performance issue, and it is something we are looking to resolve in the future. My post here details how we think about addressing this class of issue: