1.14.3 on Mac - extremely laggy on realms

Minecraft 1.14.2 ran great on all our Macs.   1.14.3 has been nothing but horribly laggy constantly.   Eating food takes 3x as long as it should.  Experience glowballs move painfully slowly – even when a player gets many at once, they only chime/get absorbed at about 1/3 the normal rate. Blocks of all sorts when broken sometime often reappear and have to be broken again. Minecarts are 3x as slow as expected to travel anywhere.   Also experiencing the game rendering//rolling shutter//screen tearing issue.   Have tried messing around with video options within the game, but nothing makes any of these issues any better.