One physical LNB for such different (apart for 13E and 19,2E) satellites?
But, OK, 4 cables coming from your dish(es), go into the switch and then to both boxes?
Instead, if you have connected only one box at the time (but this was not the meaning in your first post, where you wrote: "have one solo2 and one duo2 connected to the same dish"), it should work.
How did you set the tuner up? As SIMPLE configuration and 4 satellites (A/B/C/D) or as Advanced configuration?
Better the simple configuration.
In OBH you can also set the port of each satellite as "Automatic" and leave OBH to find the satellite connected, just to avoid errors.
If, instead, the two boxes are connected at the same time, please specify.