today i run my axis after switching from 15% to 20%. During first two tanks it choked at quick start but after third tank it run perfectly. In the half tank glow plug broke. I changed for the new one - cold. Unfortunately it started to choke again. Is it normal and i should run few tanks to let it "feel" the new plug or sth is wrong?

anyway what would be the best plug for axis with 20% fuel? Cold, warm, hot or sth else?

and which for the gs21r also 20%?

thanks in advance