So confirming that Prye actually failed their disable check?.... I'm not sure how they triggered the symbol since they knew it was there.
Pyre is at her current location (about 15 feet or so from the symbol spell that Ezabard sees), so you do not think it is from the symbol. You do not know if it has something to do with the trap (since Truesight doesn't reveal "magic" like Detect Magic would) or from some other source.
You can use your reaction (or action if you wish) to make an Intelligence (Arcana) check to determine what the spell is. Given Ezabard's Arcana +12, you will
most likely make the check! Then you will know if you can dispel it or not, if you successful identify the spell.
NOTED: your spell is on Pyre instead.
Does Ezabard believe the stoning is coming from the symbol....do I think its dispellable?
Unlikely since if the symbol had been activated, it would be visible to everyone at that point and glowing in a powerful (but dim?) light. You already made your check for that. If you get closer, you might be able to identify the specific effect of that symbol as well.
Do we notice Pyre turning to stone, was it immediate? or will it take a few rounds? if it's the latter no part of him should be stone yet, it's a gradual process but it should not impose any penalties like hands turned to stone...
For the current round we are resolving, only Pyre knows she is turning to stone. Ezabard has noticed she is not moving really, so suspects something is wrong. Vyrlim was casting this round so has not noticed yet, and Selesson was paying more attention to the hallway behind the party, but when glancing notices Pyre isn't moving and says:
"psst Pyre, what's the hold up?" Selossen says quietly
@FitzTheRuke you
know you are slowly turning to stone. So far, it is affecting your hands and legs, and the rest of your muscles are tightening up. For the present, you are
RESTRAINED (your speed is 0, you make attacks with disadvantage and attacks against you have advantage, and you have disadvantage on DEX saves), but you can still act, speak, etc.
You have the LUCKY feat. Do you want to use it to reroll the first failed save? Or save your uses? Such as for the Initiative roll?
Once I know Fitz's response, I will change the action if the new saving throw is successful.