In Better Call Saul it seems like Gus started taunting Hector even before Hector could communicate and if so, did he not tip his hand? In
Episode 3 season 6 when Nacho says he set up Lalo as he was paid by the Peruvians, Hector hits the bell and points at Fring -- is this not a cause for concern? Hector can even spell things out in a belabored but effective way. It seems that there is no way that Hector can't convey his suspicions but perhaps they already suspect Fring and Hector really has nothing to add.
On the other hand, if Gus started to taunt Hector early, his family would have found out and this alone could have caused problems or simply the nursing facility would have been told not to allow Fring to visit.