Pool dropped 2" overnight - Can hairline cracks in skimmer cause it

[MarkyMackSTL]

So we opened Saturday. Filled it, then overnight it dropped about 2-3 inches. I thought it may be the skimmer lines so I ran off the sump (bottom drain) and plugged my skimmers and filled and let it run. Again, overnight it lost the same amount and seems to be draining to about the same level. The skimmers are plugged and holding water at the same level as the pool which is just above where the water enters the skimmers. I looked all over today for some loose concrete around the entry space to the skimmers or cracks in the skimmer and found these. Funny thing is that it drains about 2" overnight and then drains another 1/4-1/2" over next several hours. That seems to correspond with the cracks and the thinner one being slightly longer than the other one. I was going to give it a quick sand to clean it up and then hit it with some clear JB Weld. Question is: Can hairline cracks cause that kind of draining issue overnight?

https://www.simplycleanlaundry.com/wp-content/uploads/2020/05/IMG_5093.jpg

[MarkyMackSTL]

Just a quick update that we did a dye test with some red food coloring. It isn't a strong pull but it definitely appears that the food coloring was being pulled to those hairline cracks. For the cost, I think I'll try the sanding and JB Weld and I'll keep everyone updated.