You can connect your PS4 directly.
Then use a optical audio cable from the PS4 to your receiver.
If your TV has an optical audio output, then just use that to your receiver.
Turn OFF ARC in your TV and the receiver.
You will get digital audio out of the TV to your receiver over the optical cable.
You will get 4K to the TV directly from the PS4.
The TV will take the audio from the PS4 out of the TV using the TVs digital audio output connection.
Digital audio over optical cable and ARC are limited to the exact same codecs. They do not support HD audio.
Only HDMI with a direct connection to your receiver will support HD audio. So, Blu-ray Disc with HD audio should be connected directly to your receiver.