Here's a list of possible reasons
Running a VPN
Using proxifier
Broken proxies
Messing around with wireshark
Living in a country where runescape is illegal
Not being aware of some network settings that you set in the past
Running inside a virtual machine/container/server/sandbox and not being aware of the network settings
It works for a few quests but it's not very ironman friendly overall
Lower reaction time on mirror mode to 50ms (default is 1000ms) and restart the client before script runs, a fresh start greatly improves performance on mirror mode (there are some memory leaks that the devs are working on for the next mirror mode client version)
Is it opening and closing the bank? When was the account created? Does it have adventure paths? In the quest tab, is there some other sub-tab open other than the quest list itself?
Yes, but make sure you reduce the reaction time to 50ms before running scripts, and it's best to restart the client before a script run to achieve best performance
Are you using multiple bot tabs in the same client? Lowcpu mode? Running inside a virtual machine or on a server? Did you use some bot manager or another way to start from CLI?