Hello and welcome to the forums. I believe you are using a pre full HDR Onkyo. While it can pass 4K/60, it may have issues with devices trying to pass 4K/60 HDR through it. This is why forced HDR from devices introduce issues when going from 24hz content to 60hz content in HDR. Onkyo did update some models for Enhanced passthrough.
Check for any firmware updates. There have been many for that model. If up to date, check for HDR Enhanced mode. Press and hold the BR/DVD button on the front of the unit. While holding it, tap the ON/STANDBY button. If “Std.” appears on the front display, tap the ON/STANDBY button to switch it to “Enh.” If not able to be updated for enhanced HDR, these steps will do nothing.
If the Onkyo cannot be updated, connecting the devices directly to the TV will enable full HDR output. Make sure to enable “Enhanced” mode for the HDMI ports in the Sony TV. Use Premium Certified HDMI cables supporting 18gbps. HDMI and HDCP specs can be confused with one another. There are currently HDMI 2.1 and HDCP 2.3 specs. There are issues when dealing with devices of the much older HDMI 1.4 spec in a newer setup but not so much with HDMI 2.0 and HDCP 2.2 devices.
To get audio from the devices back to the Onkyo using ARC, you will need to turn on HDMI-CEC and ARC in the Onkyo and in the TV. Sony calls HDMI-CEC “BRAVIA Sync.” One shouldn’t be concerned with HDMI issues Onkyo had years ago. Current models are fine. Yamaha is currently handling HDMI board replacements for 2020 models. Denon/Marantz are fine receivers but come at a premium many are willing to pay for Audyssey room correction.