Like I said, contrary to audiophile (7%) beliefs, most AVRs can power most speakers just fine and it doesn’t matter if the speakers ”dip” down to 3 ohms a little bit. That’s why I doubt it’s a power issue.
About 93% (per M Code) of the audio population only use AVR without any kind of external amps- they seem to be doing just fine. But the 7% of the population keeps in telling the 93% that they need more powerful amps.
I have seen AVR shut down due to high operating temperature, including Denon/Marantz, Onkyo. But the AVR usually shuts down, not have intermittent audio dropouts.
And if it has audio dropouts with everything - analog and streaming - then the AVR might be defective, not because it is underpowered.