Captions not staying on English on Paramount+

First, I don't work for either Roku or Paramount.  I can understand your frustration; however, if you ever have to determine the source of a low grade exploit like this, which is probably taking advantage of injecting the code into the data stream on the internet and is NOT originating from Roku or Paramount, then you would appreciate the difficulty in finding and fixing the problem.  I get a notification from Roku every week letting me know that they're continuing to work on this issue; but, the problem is probably occurring somewhere on the internet itself and not at your house, Roku's business or Paramount's business... so, sure... don't buy their products anymore, or take 5 minutes and fix it, until the next time.  I've been fortunate, I fixed the issue once, and it's hasn't come back.  All it takes is a factory reset, and Roku's devices are clever when you have to do this, the device knows most of your sites you're watching and with that and a cell phone, it literally only takes my 5 minutes to fix the issue. 

No harm is done to your device, and it could be an indication of weak security on your home internet connection.  So, perhaps the reason it hasn't been fixed yet, is that the hacker is taking advantage of a weakness in your home internet security.  I've beefed up mine, maybe you should look into that, just in case.  And I say that only to give you an idea of the scope of the problem.  The weakness could literally be anywhere, and may not even be intentional.   For example, a stray cosmic particle hits the bit stream and alters a bit on your language choice causing your system to think you prefer one language or another.  It just happens to be German in your case, others have had similar issues but with other languages.  It varies.   Just saying.  It's probably not a stray particle, but it could be.  BTW, if you figure out where it's coming from, let us know. 🙂