The 7060cx does support 25G. 7060X Series - Overview. My partial config:
interface Ethernet32/3flowcontrol send onflowcontrol receive onspeed forced 25gfull
Arista says it doesn't, only CX2 supports it. You can breakout 100G to 4*25Gb and it works. If you use 100Gb to 25Gb MSA it may not work.
Do you have it setup using MSA? I use breakout cable, no issues.