Ultra high resolution no longer available on Surface Pro 3

i7 Surface Pro3 with Interl HD graphics 5000, Windows 10 64 bit, main screen resolution is 2160x1440 and when connected to secondary display it is 3840x1600. I specifically recall having an ultra resolution setting available when previously running zwift last year- I don’t recall what it was, but definitely higher than 1080p, the only options available now on either screen. I realize neither resolution is 4k, but it should be able to downscale to my above listed resolutions as it appeared to be doing last year. (is the 1080p max currently listed actually 2k, 2048x1080?)

When running on the Surface display at full screen, while the program launches I get a message that pops up saying "Optimal resolution notification: This is not the optimal screen resolution for the primary display. The optimal resolution is 2160 x 1440 (the resolution it is actually running at, so I suspect it is because zwift is forcing lower resolution- bottom of message says igfxTray.exe).

FYI, when I first attempted to run full screen mode on the 3840x1600 display, it started full screen then switched to a smaller area of the screen but without windows controls visible. This was running what windows claims is the latest display driver so I manually downloaded and updated the latest from Intel’s site which was , after installing windows shows this as , very off, but after this update the main screen remains in full screen.

Thanks for any assistance, I really want to get back to the higher resolution!

Cheers & Happy Thanksgiving-  Justin