Replace the throttle cable with a Motion Pro T3 cable. They don't list specifically for Betas but the KTM cables fit as the throttle and carb are the same. Just check the length required.
The Motion Pro cables are sealed into the threaded end pieces and they thread directly into the carb cap. They are designed specifically to stop the cable jamming or snagging because the end has pulled out of either the throttle or carb. They are also much better at keeping wet out of the carb.
If you buy the longer version you can feed it behind the front light keep it away from the handlebars.
https://www.motionpro.com/c/t3-cables?y=2016&b=KTM#b
2020 200RR.
2014 300RR. Gone but not forgotten.