Multi Boot Menu Display keeps changing... Why?

Just recently, after updates delivered during August, my multi boot menu display keeps changing.
I multi boot Win 10, Win 7 and Zorin (Linux) and had the boot loader installed using Easy BCD. This worked fine for many months without issues.

Now suddenly the behaviour has changed, depending on whether I cold boot or restart the PC.
On a cold boot the Win 10 graphical boot menu appears on the main monitor, with all 3 options displayed, just in graphical format. (nice actually imho)
When I restart the PC the multi boot text version appears and only on the secondary monitor.

I had given up trying to control the boot menu display being shown on the main monitor. Explanation given was that prior to the Win 10 O/S starting the bios will always take the easiest route, ie. the VGA connection to the secondary monitor.

So why, when cold booting, does Windows 10 suddenly override this and takes control from the get go and displays the multi boot menu on the main monitor. As an aside, when selecting Win 10 it loads really fast with a splash screen that now states "prepairing windows" and take barely 5 seconds to the desktop. No complaints there of course.

So to restate the question. Why the change and the different behaviour between boot and restart. And how can I get the graphical display to activate on a restart also.

Any pointers appreciated.
NZTinker

No, I don't have fast startup enabled. And I don't use restore points. I have Macrium to manually save disk images after manually updating things (usually weekly) My best friend -:)

My 1st guess would of been the same as Dalchina's but it would use the "Windows Boot Manager" from a Coldboot with UEFI enabled, but perhaps during a restart the system does not "drop that low" in the Order in the Boot Code , even though we think it does while looking at the Post screen ? ie. for a faster Restart Win 10 is now closer to a Log Off than a real restart.... just a thought....

KB.