Hi @ZOS_Kevin this is the thread you asked me to create. Bit long so apologies but I thought of things the more I typed haha.

To avoid confusion I want to mention this is not that bug from a couple patch cycles ago. In that one, dragons at a certain fight spot in N. Elsweyr would become "stuck" in hover mode. I have not seen that since it was reported fixed

The issues I've noticed with Frost Dragons I have only seen in N. Elsweyr, but it can happen at any of the fight spots where dragons can be engaged.
I don't know about S. Elsweyr, I rarely go there for dragons because of the horrible FPS drop I get in some fight spots (one is near the water iirc)
But if someone has also seen issues with them in S. Elsweyr please post.

Breath Weapon
While on the ground in melee range a Frost Dragon's breath weapon often has a "descync" like behaviour.
It will begin it's breath attack facing one direction or player. You can be standing behind it and while it appears to still be facing away from you, you suddenly get hit with all the ice spikes and damage from the breath weapon. Moments later you will see the dragon "blink" to be facing you. There is no animation when it blinks around, literally like it's facing one way but the server suddenly decides it needs to be facing toward you. Very hard to mitigate this attack and survive because most of the time you don't even realize you're getting hit until you're suddenly missing half your health.
This one is common.
Worth mentioning: Sometimes with this bug the dragon's head will do this like, rapid shaking\vibrating\spazzing movement before it breathes. It's kinda B-Horror movie creepy looking.
(Side note with ALL dragons, sometimes they will start a breath attack and if the original target dodges or moves they will immediately stop the attack. This may be expected behaviour tho.)

While in flight has a similar "desync" like behaviour where the dragon makes a strafing run with it's breath weapon but you don't see the breath coming, just the effects and damage on the ground as it passes.
This one is not as common.

Worth mentioning that while the dragon is in "perch" mode and does a breath attack this seems to behave as it should, the attack is seen and felt in the same area.
(That said, ALL the dragons while in perch mode still sometimes have an odd visual where their head is visibly looking or "aiming" in one direction but the breath attack goes in another direction. Like they decided to sweep their breath attack and move their head but the attack stays rooted to the original target spot)


Fus Ro Dah
You just haven't lived until you've been Fus'd from a Dragon's backside.
Similar to the breath attack while on the ground, the dragon speaks a "Fus" in one direction and suddenly you are hit with it even though you are standing to it's side or even directly behind.
Behind is the most common form of this bug(Fus Ro Fart?)
(To be clear this is not the same behaviour I've seen where the dragon begins speaking and looking at a target, then right before "Dah" it turns it's head in a different direction and does like a smooth dude over-the-shoulder shot at you. That one is actually kinda cool and looks intentional, the sly dog)

Fo Iiz Gron
Almost sounds like "Foe Lee Groo"
The dragon will raise it's head skyward and call the shout that summons a circular ice and wind storm to encircle the battle site in a large diametre.
If you are arriving to a fight in-progress sometimes you can't see the active storm encircling the area, but the damage effects are definitely present.

Various Bites and Chomps
These bite attacks have the same desync-bugged behaviour like the others above. I've been bitten through wings, through tails, heck I've dodged and run well out of melee range and the dragon still manages to throw it's teeth and bite me.

Thank you again @ZOS_Kevin for passing this on! Dragons are some of the coolest creatures in ESO, extremely well done and beautifully terrifying.
With the Season of the Dragon event coming I hope the team can give the big guys some love and bug fixes.

These are all the ones I notice frequently but if I notice or remember others I'll update this post.

If anyone else notices issues with dragons, not just Ice please add posts here!