I just received my Shapeoko 5 Pro with Carbide Compact Router on Friday. I was able to put it together with seemingly no problem, until step 5.4.2 (Page 35). The instruction said tighten 4 M6 screws to lock the router in place. I can only find two. The two bolts are tightened as much as possible, but I can pull the router straight out of the spindle mount.
I believe the instructions are just confusingly worded — the 4 bolt reference should be to to 4 bolts which hold the mount to the carriage.
There are only two bolts to tighten the mount around the spindle, and there’s a lot of metal to bring into play — be sure to use the square end of the hex key and to switch constantly between one and the other — keep going until you approach a point where the hex key wants to bend rather than turn the bolt (but stop before then).
Just echoing Will here, this was the part of the build that gave me the most pause. When I would tighten the top screw too much, it would kind of “bind up” and feel like both were really tight, even when the router would easily pull out. So even when I was going back and forth doing the tiniest turns I could muster, sometimes one turn would be too much, and I would have to go back it off. You should be able to feel a consistent increase of torque required to tighten the screw as you switch back and forth. At least in my case, you shouldn’t need feel like you have to force it tighter at any point… but that might depend to heavily on my own experience of how much force is too much, good luck!