This looks pretty good.
https://www.denon.com/en-us/product/special/avr-s950h-r?utm_term=product&utm_source=criteo&utm_medium=cpc&utm_campaign=remarketing_dynamic
I haven't shopped for an AVR in over a decade as I've long since transitioned to separates. Given that the deal you've identified is for a refurbished Marantz unit, you might as well go ahead with it . I doubt you'll find anything new with comparable features, especially in todays marketplace.
I think you'll be pleased with these choices. Do you have any plans to actually use HEOS? If not you might look for a Denon model that omits it and offers a discount.
To make an intelligent choice of a replacement receiver a little information is needed about your current environment. For starters...
Approximate room size [Sq ft or Cu ft]
Number of speakers
Manufacturer/model of Left, Center and Right [LCR] speakers
Impedance of LCR speakers
For the...
I agree with @ManW_TheUncool in that the problem has yet to be fully diagnosed. The best solution won't materialize until it is. According to what I see on Crutchfield [see below] the receiver should not be a source of any audio quality issues if it is good working order and you're using good...