This is likely being caused by your Sony TV trying to process the PS4 audio signal as it passes through your TV, as the Beam will only play the audio as soon as it gets it from your TV.

Perhaps check your TV user-manual to see if your TV may support ‘pass-through’ of the audio through its HDMI ports and enable that feature in the TV settings. If not, then you may find that a power-off of ALL products for a minute, or so, ’may’ fix the issue.

Sometimes swapping the TV HDMI-ARC connection for an Optical connection (using the adapter supplied with the Beam) may also help to fix this issue, but if all else fails, then you may have to resort to using an audio splitter/extractor and bypass your Sony TV altogether.

Here is one randomly chosen audio extractor/splitter device for you to see, just as an example, but I suggest you thoroughly research these type of devices before making any purchase decision:

https://www.amazon.co.uk/Tendak-Switcher-Optical-Toslink-Extractor/dp/B07YD2CLMY/