(mod in question: https://mods.factorio.com/mod/Better-Power-Armor-Grid).
Hello. I've recently been playing the Krastorio 2 mod along with the "Extended Vanilla - Power Armors" mod, and just reached the research tier where I could, and did, research "Power Armor MK2" (I'm being pedantic because of the many tiers). When I built the armor, however, I found I could not insert any of the power armor modules (such as batteries (the K-2 ones), power sources (the K-2 ones), and personal roboports (K-2 ones) ) that are bigger than 1x1. The 1x1-sized ones (nightvision, belt immunity, etc.) could be inserted. The nightvision item, BTW, is the Krastorio 2 version (if I highlight the item as if to craft it, it shows dependencies of "base mod: Krastorio 2" (others are from Nanobots).
I confirmed - by removing the "Extended Vanilla Power Armor" mod, and then reinstalling - that the problem was specific to the power armor mod (and Krastorio 2). If I removed the power armor mod, all items could be inserted. When I reinstalled the power armor mod, they could not. BTW, by "not insertable" I mean that when you drag the items into the equipment grid, a hashed out pattern appears, and you cannot "drop" the item into the equipment grid.
When I'm building the armor, the mod dependency that shows up is "base mod: Extended Vanilla Armors : Krastorio 2." One thing I noticed that in the research tree, only "base mod: Krastorio 2" shows up. I don't know if this is important or not.
I should note that the "Power Armor" (i.e., MK 1) worked correctly.
I have no idea as to which mod is causing the issue, but thought that you might be interested. I've noticed that Krastorio 2 has marked several armor-related mods as conflicting, so this may be typical for such power armor mods and Krastorio 2.
FYI, and thanks for a great mod!