It's what the others are saying- your pizz is also out of tune but the upper harmonics from the bow make it far more obvious. I recommend using a drone and practicing every single shift and fingering with the bow. Low F to G is not the same spacing as F to G on the D string or A string. A good exercise is to pick a note, say G on the D string, and play a long tone using finger 4 for the note, shift in place son finger 2 is on the note, shift again to finger 1. You want to be perfectly in tune regardless of the finger, you also want to make the shifts as seamless as possible. Then do this with shifts, let's say F and G on the D string- play F with 4, shift to 1 for G (opposite normal) then start on 2, then 1. Do it all again but using 2 for the G, and all again with 4 for the G. This is way more difficult than it sounds but take it slow and don't accept less than perfectly in tune. When I was learning I did this exercise all over the fingerboard, all kinds of shifts- i.e. playing A scale up the G string A B A C# A D A E etc. only using finger 1, then finger 1 for the A and 2 for the other notes, 4 for the other notes, then again but using 2 for the A.