GUI timeout and master node memory-hungry

Hi, I experience some problems with my rancher/ kubernetes cluster.
My cluster consists of 4 nodes, 3 workers and one master. The master is a VM.

I have a project, which has only one namespace. But this namespace includes 16 services (deployments and statefuls).
Every time I enter into this project, I have to wait about 2 mins or more.

If I choose an other project, with less services, the browser opens the page almost immediately.

In addition, the master thirsts of ram. The master has 17GB ram and 6 vCPUs with high priority.
After a week, if not a few days, the VM runs out of memory and I have to perform a reboot.
Then, I run the following command:
rke up update-only

Could you provide me any kind of advice?