I have a problem with my current set up, and I think it is a software/system problem. I have a monitor connected to the dGPU (RX480) and another to the iGPU (i5-4460) via motherboard. They both work in W10 and other distros. I think I haven't been the only one with this problem as I have read, and I'm looking for someone who had this problem too and if they were able to fix it. I have realized today I can just connect the monitor to the dGPU via DVI but still think the devs should take a look at it. I made a post in the dev.getsolus.us with some more info if you are interested. https://dev.getsol.us/T8904
Other people with the same issue unresolved:
https://discuss.getsol.us/d/3088-setting-up-2-or-more-monitors
https://dev.getsol.us/T6800
Also Thanks for the devs dedicating their time into this proyect! I installed it last week and I love it!!
Edit: As I said, I have connected it to the dGPU via DVI and it worked instantly.