Hello, same problem with QLED QE65Q95T and optical audio to Marantz ND8006. We had QE65Q90T (without one connect box) at home for few days for try and was working perfect. Looks like problem with One connect box + toslink.
I'm having the same issue with a Samsung The Frame 2019 65", connected to a Quad amp with a build in high-end Sabre32 DAC. Sound is good for 10-30 minutes and then the issues start with the sound of clipping out for a few milliseconds - this happens every 6-8 seconds.
This is very, very frustrating and disappointing for a TV at this price (or any, really - never had issues with much cheaper TVs).
I even bought the Argon Audio NanoDAC from HiFiKlubben, as @Supermanders mentioned, but this did not fix the issue for me.
TV software is up to date, and tried a few restarts/resets.
Happy to hear if anyone finds a solution here.
I have Marantz ND8006 with Sabre DAC (ESS9016) too (connected to Marantz PM8003 amplifier), maybe that is the problem. I also have cheap Fiio d03k DAC, I tried samsung one connect box optical output -Fiio d03k DAC - Marantz PM 8003, it works without problem (sound quality of Fiio is not as good as with ND 8006). So there is probably problematic combination Samsung One connect Box - Sabre high end chip???
Looks like a pattern... Samsung One Connect Box + a Sabre DAC chip = regular audio cut outs.
I have the Cambridge Audio CXA81 that uses a ESS Sabre ES9016K2M DAC chip, and have the same issue. (Fiio Taishan D03k works ok)
A previous poster with the Arcam SA20 had the same issue (and uses a Sabre ESS9038K2M). Arcam were able to provide a fix for them... Cambridge Audio havent been very helpful to a couple of us, as mentioned before.
Do try contacting both Samsung and your amp manufacturer.
Makes sense - the Samsung One Connect Box has a very poor quality optical out with very high jitter.