Font ukai looks awful on ubuntu mate 16.04 beta 1

AR PL Ukai looks well on ubuntu mate 15.10:

but in 16.04 it looks awful.
How can I get the old appearance back?

here is in iron , 16.04

here is in chrome, 16.04. It must be Abyssinica SIL not Ukai

I tried Serif and Sans that firefox is using them for default. Much better now.