All ways best to test stuff before you modify it in anyway (even removing stickers) for warranty purposes.
check the card for scratches in the traces where you removed the sticker.
check the power cables going to the card. If a modular power supply see that they are plugged in all the way on both ends.
You said you are using a dongle for the monitor, try a different one to rule that out.
"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."