Missing number math problem

Question

I have 4 boxes with numbers and one with a missing number. Top left box squares from left to right then top to bottom are 2, 6, 5, 2. Top right box is 8, 4, 6, 7. Bottom left is 9, 14, 8, 14. Bottom right is ?, 11, 8, 6. There’s also a central box around the inside numbers of all the boxes.

Answer 1

Does it look like this?

2 6 8 4

5 2 6 7

9 14 11

8 14 8 6

The only thing I've come up with is this:

Looking at the four corner groups of 4, counter-clockwise from top right, the sums are 25, 15, 45. That suggests that the 4th group might also be a multiple of 5---eg:

10 11

8 6 Total = 35

However, the center square cannot also be a multiple of 5......so I'm stuck