Sounds like you’ve received some good advice about sitiing and some other topics. I’ll weigh in and hope not to confuse the issue. First off Gumpo/Gunpo isa very slow growing, fairly hardy azalea with exceedingly tough wood with big flower blossoms susceptible to rot.
What I’m seeing appears to be incidental damage from coming out of the winter, and some of the buds appear nipped or blasted, Lots of the new growth appears ok. That’s my first guess just looking at the tree, If so and your media is not a background issue, things will get better over time.
Yet this is a somewhat tricky time for azalea issues. Usually winter problems have shown up by now and are getting resolved while spring issues are just starting to kick in. This includes my most unfavorite springtime issue in Puget Sound, root fungus. Our rain patterns can really hasten root rot with poor choice of media.
Given good media, all one needs to do is chock up one side of the pots, or entire benches, and with good drain holes drilled in the ends of the pots, all will be well. Since your azalea is in plastic, this is easy to set up. You can use wood blocks or small rocks
Given poor choice of media, improper root washing when changing media, using two dissimilar medias, one in the care, one on the outside, things can go downhill rapidly. There are some things you can do. My favorite is Hydrogen Peroxide 3% cut 1:3 with water for a once or twice during the Spring drench if you feel root issues are kicking in. Then back up with 2TBSP 3% H2O2 in Qt Water. It’s the most environmentally friendly and very effective. I rarely use anything else on azaleas.
@Mellow Mullet also mentioned a product he finds useful In his neck of the woods.
Not so sure when you say your media is hard? Was this azalea root washed and put into the Kanuma/Bark media, or was the original soil in the rootball core still intact when you added the new media.
If it’s the former situation, I’d say re site and watch.
It the latter situation my advice would be to properly rootwash the entire core clean now and put in one good draining media. Putting in cores is a half measure that will help the tree move along, but the issue will still be possible….and the timing is right just to totally fix the situation.
I use 90/10 Kanuma/pumice and it works for my trees, yet there are plenty of other good azalea media choices out there. My advice is to choose one that already works for people with lots of azaleas.
But your tree, your choice
Good Luck
DSD sends
Three days in bed was enough for me.