Add another one to this list. I have the EXACT same problem.
Surface Pro 7 (SP7)
2 external monitors: HP 27f & HP 27es
I have worked with MS Support and replaced the computer followed by the Surface Dock 2 (SD2). This display problem has persisted since April 2020 when the purchase was made.
The current workaround is one monitor plugged into the SP7 USB-C and the other into the SD2. If all three monitors don't fire up when the computer is turned on (typically the USB-c monitor fires up reliably), CTRL-START-SHFT-B (go figure) from anywhere
between 1 and 10 times will bring up the SD2 monitor (all 3 are running).
Previously, with both monitors plugged into the SD2, the CTRL-START-SHFT-B sequence, between 1 and 30 times, would consistently bring all monitors up.
Since there is a keyboard sequence to get all three working with a SP7 and SD2, this has to be a software problem.
Microsoft is apparently ignoring their software problem.
Looking forward to a report on a fix on this extremely frustrating issue, short of acquiring a different setup.