win 10 + Ubuntu 18.04 -> Lubuntu 20.04

So I’ve run into trouble installing Lubuntu 20.04 on my Dell inspiron (intel Core i5 7th gen. 8mb ram 1tb HDD).

I previously dual booted with windows 10 and ubuntu 18.04 with no issues.

Decided to switch entirely to Lubuntu. Created bootable Lubuntu 20.04 usb, deleted the partition, booted from usb, installed Lubuntu without internet, clicked finish and restart, removed usb and hit enter.

When booting up my laptop still went to the GNU grub, and only gave me the option of booting from ubuntu, when i tried that got a constant black screen. I can boot from usb and lubuntu works fine, but can’t without it.

Any ideas?