I read something saying SSPX Priests do not have the right to be called “Father”
Yes, what else would you call a validly ordained priest of the Roman Church?
While they may have been ordained validly…
Suspension a divinis 
Although the 1988 excommunication of the four SSPX bishops was remitted in 2009, the SSPX bishops and priests were still unable to exercise any episcopal or priestly ministry in the Catholic Church.
That has no bearing. They may be in schism, but that doesn’t change the repect we owe them as priests. Because they are priests. Would you call an Orthodox priest anything but ‘Father’?
I read something saying certain restrictions the SSPX Priests have include the right taken away of being called “Father”. I’ll need to look for it. But until then, I’m not sure
Right, shout ‘you filthy schismatic!’ at them then. I’m sure that’ll help unify our Church. Look, if a Protestant pastor asks to be called ‘Father’, call him Father. If an Orthodox priest introduces himself as ‘Father’, call him Father. And if a validly ordained Roman priest whose Society has an irregular status in the Church asks to be called ‘Father,’ for heavens’ sake, call him Father. It’s called basic human respect. Then pray for him and all SSPX priests, that they may once more find solace in the Church.