Why does my computer not boot the bootable stick, why is everything set correctly in the Bios Manager?

It does not boot from the PC, but it does something from the laptop, so something is wrong on the PC, moreover, I used to have Windows on the PC, then I had created a bootable Linux Ubuntu stick and then booted and installed it on the PC (think on the hard disk so speak the Windows overwritten) everything worked perfectly but every time when starting normally my computer shows when booting up without any bootable stick for mili sek. The booting does not work because the file was not found, but then he boots up as if he had found it so somehow bug-like now and when I plug in a bootable stick nothing happens, it just does not boot and boots to Ubuntu as normal, I would like to boot up to Lubuntu or MX Linux but as I said the PC simply does not recognize the bootable stick but my laptop does so I'm somehow not smart now and hope for your help, I have the following pictures from my Bios Manager made and maybe you recognize a mistake.

Switch off SecureBoot

Please have a look at how the boot order is set in your bios. If your hard drives are specified in the first 2 positions, then of course an attempt is made to boot and the USB slot is skipped because a bootable OS is usually already installed on the hard drive. Furthermore, depending on the bios manufacturer, you also have the option of pressing a specific key F9 to F12, where you are asked where to boot from. There you can also choose your USB slot.

Hope that helps.

I had done it now, the problem remains…

Sorry just saw the screenshot that it is already on removable device. In that case, look that you put the usb stick in the slots that are directly on the board (with the midi tower usually in the back) the front panels almost do not rule. If that doesn't help then maybe usb slot futschikato? In that case, you could create a bootable disk as a cd / dvd over the other pc. Although old-fashioned, it is still a workaround.

It is not only enough to switch off the Secure Boot… You also have to switch off the Fastboot option… Then you switch to (security or secure) in the BIOS and set it to (enabled). Everything with… F10 … Save, now it should actually boot from the stick function.

Partition scheme MBR or GPT?

Only had a Win10 with GPT with Rufus and it didn't work. I put it back on the stick but as an MBR it worked.