[v4]: First compiling on Next 15+Docker takes 30+ seconds and HUGE amount of CPU

[lentscode]

So I'm currently upgrading to v4 from v3 in my Next app, and everything works well. However, when I'm in dev mode, the first compiling takes A LOT, about 30secs, but then everything works faster than before, about 2 secs for each page compiled.

I don't know if this behaviour is expected or not, when running next build everything works fine. The issue is only that first compile on dev mode.

UPDATED:

Actually the problem is on Docker: when running on a Docker container the first compiling takes a lot of time and A LOT of resources.