This should not be the case by default.
Can you try enabling the “Enable Debugger?” option from settings > Inactive Logout page and see if that debugger is showing for you? i.e when you check the “disable Inactive Logout” from role based tab.
For example: https://tinyurl.com/2osvadkg
Please note you need to refresh the page after saving the role based tab section, in order to reflect the change – I know that does not make sense but thats how it is right now.