When you use the AVR and it’s in sync, what are the connections between AVR, TV and PS4?

On my old Av kit is was basically the same setup - PS4 into TV and Virgin box into TV and HDMI Audio out to Av setup - I tried optical as well and that’s the same - using same leads all in the same order

That surprises me (although I am not disputing it), because Sonos say that their HT products don’t do any sound processing, and just play what they receive when they receive it.  My own experience supports that, in that when I have bypassed the TV for audio, lip sync issues have disappeared.  I have done this using an optical switch and a Playbar in the past, and I am currently doing it with my Arc, using an HDFury Arcana.

One experiment you could do, if the PS4 has optical out, is to run the optical and optical-to-HDMI-ARC converter from the PS4 rather than from the TV.  Whether or not you get lag would tell us a lot.

Based on your suggestion I did link PS4 direct to Sonos via optical and boom it’s in sync - so issue is TV although no way in tv to switch to a bypass mode - should have bought Sony! Anyway have just bought an optical switcher for my Virgin box and PS4 pro so they can go direct to Sonos optically and bypass tv all together- not pretty but sound quality and sync will  hopefully be solved - will update 

Sounds promising.  I have experienced this problem with Panasonic and LG TVs too - maybe we should both have bought Sony, although I don’t know if that would have been any different!  

By ‘bypassing TV audio’ I meant exactly what you are doing - not sending the audio to the TV in the first place..

Yes please post back with results.

Okay have managed to create a decent work around solution that is giving me Dolby 5:1 DTS from all sources, however it did require additional (not expensive) kit to make it work. After linking the PS4 direct and the Virgin Tivo direct it was clear it was the TV that was causing the delay but only really on the PS5 input - however as this is the majority of where I spend my time (amazon and Netflix through PS4) it was important to get this working. I invested in an optical switcher - eSynic Spdif Toslink Switcher 3 X 1 Digital Optical Audio Switch with IR Remote Control Support LPCM2.0 PCM2.0 DTS Dolby-AC3 Dolby Digital DTS 5.1 Dol - and a new optical cable and now with the flick of a switch I have perfect synced audio for both my devices. It’s annoying that I can no longer use the Tv remote to change volume but its a small price to pay for what is a really good sounding wireless setup that provides me with Airplay audio in my living room as well.