Problem solved! Thank you to u/Bradmck over at Reddit for the resolution. For anyone that has a newer version of this board: Load RouterOS 6.49.2 and then follow the install instructions on https://openwrt.org/toh/mikrotik/rb750gr3
All versions prior to this does not work (I only tried 7.1.1 after that version and it does not work either).
This worked for me and I hope that it will work for you