To reproduce:
1. Click 'make chart';
You will see that tick label font is the same as everywhere else
but it is expected to be of size 20
2. Click 'set tick label font'
The font will be applied
1. Click 'make chart';
You will see that tick label font is the same as everywhere else
but it is expected to be of size 20
2. Click 'set tick label font'
The font will be applied