Incubator Issues

I have two incubators. One for my leopard geckos. One that I made from an old mini fridge that stopped working and the other is the zoo med reptibator. The one I made works fantastic, I’ve hatched out a good amount of tsf from it and I’ve only had two cases where geckos hatched out with problems. One had a stubby tail and the other had leg problems. The one I purchased is used to incubate males. I haven’t incubated a ton of males only a handful, but I’ve had more hatch out with deformities and problems than not and I’m not sure why. The male one is set to 88 degrees and it takes about 36-38 days for the geckos to hatch. For both incubators I set up the incubation cups up the same why 1:1 water and vermiculite by weight and leave them to incubate. This is what’s leading me to believe there’s a problem with my male incubator. I’m planing on buying a new male incubator, does anyone have any they recommend?