No issues here noticed with the Sonos Arc/Surrounds and not seen any reported recently since the latest S2 App update - maybe the issue is with the source device perhaps? Try power-cycling the entire HT setup including the TV etc.

If problem persists, maybe add a bit more detail here about the make/model of TV/devices connected and the settings you are using on that device and in the Sonos App. Also provide some examples of the audio sources you’re playing (device/App/Movie/Show/Music source etc.) and, if relevant, what codecs are shown in the App when playing, either on the ‘Now Playing’ screen, or in the ‘About My System’ (Audio In description next to the Arc in the list of devices).

Maybe then someone with a similar setup can comment and perhaps see if they have a similar issue.

The version of Apps in use may assist here too and state if using Trueplay/non-default EQ settings etc.