I'm thinking it's probably a summer bolete too now, no staining when cut, smells lovely and nutty, I gave it a little nibble to rule out bitter bolete, it tasted like hazelnuts and scrambled egg, so that just leaves me with summer bolete and cep
Just to add to this, upon further research the summer bolete regularly cracks on the cap, and the net is known to turn from white at the top of the stem and get darker towards the base, whereas cep seems to stay whiter towards the base. Hopefully that makes sense!
If it helps, I'm pretty sure I've seen them for the first time this week myself on beech too. Easiest to ID if you get an above and below pick too. They should have a kind of translucent layer to the cap if you look underneath.
It was getting dark and my phone was struggling but I'll be back that way tomorrow and will double check. I don't plan on eating them or anything but I'd like to get some better photos. You can kind of see the translucence in this photo though.