It looks like you have corrupted other configuration files and deleting them will no longer fix it.
It's not good to play the configuration manually if you don't know what it will do - you don't have a backup and you'll have to start over. Back up at least the iperf configuration and you can start again by resetting to default values .
Turris Omnia with OpenWrt 21.02 - Tested
Linksys WRT3200ACM with Gargoyle 1.13.x
TL-WR1043ND v2 with Gargoyle 1.10.0
http://gargoyle.romanhk.cz custom builds by gargoyle users