Need help from comrades -left arm strength-

Hello! I’ve finished my ladders with the 16kg kettlebell, and now I’m working on the 20kg.

So far I’ve managed to reach the 30 reps on the right arm ( 3 rungs ) but on my left arm on the very last repetition I can press the weight only halfway….

Now it’s the second week that I’m stuck there and it’s starting to be a bit depressing… It’s like I can’t generate the same tension of the right arm.

What can I do? Step back for a while on to 16kg, stick to the 20kg or what else?

My training week is:

Mon – Medium C&P and Medium swings
Tue – Variety ( PTTP deadlifts , TGUs , kettlebell squats or light jogging/light swings)
Wed – Light easy C&P and Easy Snatches
Thu – Variety ( PTTP deadlifts , TGUs , kettlebell squats or light jogging/light swings)
Fri – Heavy C&P and Hard Swings
Sat – Off
Sun – Off

I’m 35 year old, I weight around 150 lbs for 5 feet and 9 inches, my diet is balanced and my sleep is regular.

Many thanks,
Anqui