I see that her winrate fell by about 3% across the board, so something surely did happen to her.
Q build seems to have the worst, a bit short of 45% winrate which is already significantly bad and also statistically correct due to being most popular.
Her best build is E (about 50.5%, which is also unusually low) which I get is more cooperative / self-sustain (slows / regen) which was a fad at some point. It has been the go-to for a while (and many denying it being so), it was sitting at 53% and it’s the only build I could win with recently.
I don’t play her anymore but my memory is that I would play Q, heal excessive amounts and achieve nothing with it. Also (as mentioned above) in critical fights I’d usually fall below the 75% threshold and become a cripple (instant 50% healing reduction due to cooldown plus another 50-70% reduction due to health loss - easily down to 25% Q throughput in teamfights). Yes, I would pop dragon form whenever I could to avoid / remove that.
Changing W is challenging as players expect the 3s delay, and play accordingly. Granting Protected for the 3 seconds would make it utterly overpowered, I suppose. Half the roster, pretty much every new hero has a hard counter for it: Deathwing several, Mei several, Tassadar several. OId ones, too, including Ana, Malfurion, Kael’thas and again Tassadar.
I think her talents contradict her design, or she is simply Nazeebo on steroids: needs a lot of time to come together. Level 1 Q talent just makes her lose health more often, to heal less - quest is to get 7 to fix that. The W talent at 1 has no effect until 15 globes, I think it should spawn globe baseline and upon casting, simply.
The reason I stopped playing is because the better I was, the worse we lost. I lost a match where I had 200k healing against enemy 50k. Few years back I noticed that her healing made my teammates ultra confident, so I would die once, and then my team would start feeding like a whole bunch of idiots and couldn’t stop until we lost.
Overall, I think she needs a talent review.