I cannot post to the H6 forum so I cannot reply to @renedis with the link to download the Armbian_5.88.190601_Orangepi3_Ubuntu_bionic_dev_5.1.5 file he asked.
For him and other users that actually cannot run the Ubuntu image for Orange Pi 3 I uploaded in my OneDrive the working image: Armbian_5.88.190601_Orangepi3_Ubuntu_bionic_dev_5.1.5
PS: please can someone move to the Allwinner H6 forum? Thank you.