iiyama ProLite E2483HS-B1 osd locked

details:

monitor: iiyama ProLite E2483HS-B1

monitor specs: https://iiyama.com/gb_en/products/prolite-e2483hs-b1//1000

current input cable: HDMI (from Raspberry Pi 4 Model B)

problem:

im using a raspberry pi 4 to display over hdmi, which works fine.

but I want to connect a HP ProLiant MicroServer (HSTNS-5151 regulatory number idk anything about the model number as its pretty old, VGA output only) to the same monitor using VGA.

the monitors osd menu is locked and wont let me change the input source from hdmi to vga

google hasnt helped me:
ive tried holding the menu button for 10 seconds and anything related to holding buttons or plugging and unplugging or even both

ive tried just using a vga but the monitor is only looking for hdmi input

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if this looks like a template its because i copy and pasted my message from r/techsupport which hasnt given a response yet