I use a Raspberry Pi 5 8GB to run Weewx (version 5.x).
This computer is only used for this task.
I notice over time that the amount of memory used increases regularly without ever decreasing (see attached illustration). I tried the command
This command is effective since it indicates to me in response to the
"free" command a return to the minimum state of the memory used. However, curiously, when the terminal is closed, the value of the memory used remains identical before the intervention in my WeeWX records and of course continues to increase!
If I reset the raspberry, we find a used memory value of around 1GB (see illustration).

Is it normal to see this used memory constantly increasing when only using WeeWX?
And how to empty these caches in order to find maximum free memory?
THANKS...