If you are using a flash drive, if you can open the Boot Device Menu or go to the boot options in the Bios, you should see the Flash drive listed. It may be listed twice, but one version should have a UEFI or CSM or some way to identify it. The bios may have a boot override option where you can pick the flash drive. If the recovery flash drive was made from Windows 8.1, it should be available to choose.
Could you get us a picture of the bios boot options you show?
I will see if I can find the user manual on your system to see how booting works for it.
Edit: In the Owner's manual, the only reference is on page 27 and talks about the device being listed on the Boot Device List. Are you able to see the Boot Device List...