You must have turned off "Append session name to temporary path" and turned on "Keep temporary copies of remote files in deterministic paths".
https://winscp.net/eng/docs/ui_pref_storage

Change either of them to fix the problem.

Look at yoir settings. By default my editor (vscode) put it into AppData\Local\Temp\scp%session number%\etc\hosts ie different for each session (5.15.9)

I made notepad++ as default editor. I connect to server and then double click a file to open in notepad++ and save in notepad++ so it automatickly changes and uploads related files.

When i open two linux servers both having smae path system,
for example i open etc/hosts file in server1
and again open etc/hosts in server2
if i try to make changes in server2, it also tries to write changes to server1.
Because each connection doesnt have own folder in windows but they all have c://Temp/winscp/etc for example.
I think each conenction has to be downoaded to own folder in TEMP.