VCORE 3.1 300mm weird angle on Y axis

Hi! I've been busy for quite some time and my VCore 3.1 has been collecting dust during this period. I changed the toolhead from EVA 3 to RR Toolhead 1.0 in january, but from that time until now I haven't been able to test the printer thoroughly. I'm seeing that all of my first layers have lots of inconsistencies, where I can see the layer either perfectly flat or super wonky and with lots of issues as the toolhead moves over the bed. I was currently rechecking the comissioning guide and I saw that my bed is anything but flat. Before doing anything with the frame I want some advice on what can I check first so I reduce the possibility of making things worse. Seeing the mesh I seems that my Y axis is bowed closer to to the front part of the machine, but obviously I don't see anything strange by looking the printer.