Maybe need to try different graphics cards.
I think these fonts shall be load into video memory.
If testers and devs can't reproduce this problem, they can't find a way to solve it even reported.
When the VISIB RANGE in options set in LOW, there is another cockpit and canopy:
It seems these two cockpits and canopies are not at the same position. It's backward a lot compares to the "hull model" cockpit.
This is in 1.5 OB.
I can see other players moving their heads, sticks, throttle and rudder pedals in an online game now. This kind of data transfer is also required for cockpit sharing, such as L-39. It's possible I think.
The artedact boxes look like the "missing texture" image. Did you try delet the "Fui/Fonts" then repair Dcs, and install those fonts in "dxgui/skin/fonts"?