MacBook 16-inch Fan Noise

try disabling Power Nap, a work-around for a completely different problem, but worth a try for what you just described.

.

my system has always ran at 18w on the radeon card, so again.. 10.15.5 have done nothing to fix this issue.

The most productive thing you can do to make the engineers notice is to report your setup / temp / wattage / fan speed over here: https://www.apple.com/feedback/macbookpro.html

does this with any dock attached, even open the Mac is going full blast fan loud as ****.

Likely due to being forced on External GPU for any output even if its low load.

Change the refresh rate on your 16-inch MacBook Pro or Apple Pro Display XDR - Apple Support

The best way to reduce wasted resource on your Mac is to drag and drop Chrome, a NOTORIOUS resource hog, into the Trash.

Does you display have DisplayPort connection? Is the result the same over DisplayPort?

Precisely:

Contact - Official Apple Support

Don't use the external monitor you do via the connection you do during Zoom calls, problem solved.

The only solution right now is to return it.

Have you tried to connect your laptop to a new type of monitor i.e. LG 27UL850-W 4K HDR with a USB-C cable without any adapters?

I've never seen that, ever, on mine.

Have you contacted Apple Support directly?

Contact - Official Apple Support

I have the same problem but only when I have an external monitor connected to my new MacBook Pro 16 i9 with AMD Radeon Pro 5500M 8 GB, I also have an 2018 and 2019 MacBook Pro 15-inch with similar specs and I have no problem with those machines, it seems to be a problem related to the MacBook Pro 2019 16-inch with i9, I think it's a software issue and not a hardware issue but we'll have to wait until Apple acknowledges the issue. I called Apple support yesterday and they told me they don't know about this issue and they told me to reinstall MacOS (it didn't fix the problem). I hope they come out with a solution soon because I really like this new MacBook Pro but if they don't fix it soon I will return it and I will have to go back to the MacBook Pro 15-inch.

yes, this is also the one I tried on three machines and they all have the issue. However, I read a comment on in a similar conversation like the one we are having here, and he claims that when he downgraded the graphic card to "AMD Radeon Pro 5300M" he is having better experience; so I am trying to see if his case is an outlier or it is really the graphic card we have is the culprit

Undoubtedly the higher performance graphics card generates more heat, and it generates more when driving an external monitor.

Driving an external monitor is also what would sometimes cause MacBook (not Pro) laptops to go into thermal shutdown when performing heavy graphics operations.