I can allways replicate F2 not working and also F2 that does work.
NOTE: I am using HDMI port, not DP (dont know hot this is on DP, since I dont have DP-HDMI conversion cable).
In my workplace I have two sets of monitors... connected to one allways works, connected to other one does work once out of 30 tryouts (I didnt count but will speculate here).
At home I have Yamaha AVR on which NUC is normally connected and AVR is connected to Samsung TV.
In this scenario F2 doesnt work (or it works again once out of cca. 30 tryouts).
If I connect NUC directly to TV then F2 allways works.
When F2 doesnt work it freezes NUC totaly (needs to be powered off with a button... CTRL-ALT-DEL doesnt work at all).
Intel should take care of this problem (which is present already for years).
I think the BIOS freezes on F2 action if somehow doesnt recognises the display, even doe the picture is up (maybe something with EDID???).
@Intel:
Please, take this seriously and do a working BIOS ASAP.
I am prepared to take a test trip for you (Intel) on my equipment... if you need, just contact me.