I recently registered here to inform others that my situation was quite similar to the one described in this thread. I own an Octavia built in April 2023, and apart from the occasional infotainment restart, I haven't encountered any other issues.
The infotainment restarts were sporadic and not very frequent, although they became more common during a recent heatwave. Roughly 30 seconds after starting the car, the music would stop and the infotainment system would restart itself. Sometimes it would happen twice in a row, and other times three times. On the head unit, it would display the message "Audio unit not available." However, after a successful restart, the issue would disappear.
Currently, I'm using version 1900 of the software, and my dealer hasn't informed me about the availability of the 1941 update just yet. They have scheduled some other replacements for July 4th and will bug them then about it. Following the advice given by other users here, I changed my location to incognito mode. Since then, I've started my car four times and driven some kilometers without experiencing any infotainment restarts.
This might be a temporary solution (I'm not sure yet; I need more time to test it) until the 1941 software update becomes available. Does anyone know if this update will be delivered over-the-air (OTA) or if it requires a mandatory installation by the dealer?