Windows 10 won't allow Grub boot menu

[Mattjaccino]

First, I mean to say "I can't I boot into Ubuntu." I installed Ubuntu into my laptop for the second time after wiping the partition from the first one. I don't know if it is the newest Windows update but the Grub menu doesn't show up anymore when I power it on. It was a couple of days ago, but not today.

I tried going into Ubuntu through the USB I installed off of and changing the boot order through efibootmgr, but it didn't work.
I go into the BIOS but the Grub boot menu is not even an option on the list.

I just want the Grub boot menu back.

I am using an Acer Aspire E5-575G-562T with UEFI BIOS.

 

[t53186]

DO you have secure boot enabled in BIOS?

 

[Mattjaccino]

DO you have secure boot enabled in BIOS?

yes, but I always had it. I know for a fact it was working 2 days ago, and I never touched the BIOS settings or anything else.

 

[t53186]

If you have uefi and secure boot enabled and loaded win10 you may not be able to dual boot.

 

[Mattjaccino]

If you have uefi and secure boot enabled and loaded win10 you may not be able to dual boot.

I was already dualbooted. Like I said it worked just fine, I just want to know how to fix it because I think the newest update changed something.