Memory (RAM) grows with pages generated

[ipatate]

The next.js app memory (RAM) grows with the number of pages generated.
We have a lot of pages (20 000) in this app.
After inspecting the server, it looks like, the memory grows with the string of each page generated by server side.
The memory grows progressively up to 1GB quickly and continue to grow.
Have you already have this problem ? How to fix memory with GC ?

It's a self hosted server.