Ive been following the recommended flora series nute schedule and i just realized ive been giving week 1 nutes still.... that Might be the problem.. i was really worried about overwatering and starting nutes too early.
Coco needs fed it has no nutrients. I know you added worm castings but you need the bacteria to break it down.
I'm not a coco grower but have seem more than a few grows and have a decent understanding. Other may have different advice for you so take this with a grain of salt.
I would feed at week 2 schedule that you posted. Never let coco dey not even the top.
Imo you need to mix a solution at week 2 of that chart and saturate the whole pot. Normally you water daily but with such a big pot I would be surprised if you can't go 3-5 days.
The coco should stay over 90% saturated you can't let it dry out. I think 3-5 days would put you there for now until the plant gets bigger. But if the top dries you need to water again.
When you water you want to water thoroughly so you get runoff of about 10-20% of what you add. It's will take about 4gallons of water to do this the first time and from there you water with about 1/3 of a gal at a time. If you get 10-20% of that as run off your good. If you don't get runoff you need to add more and increase the frequency a bit. If you get more than 20% you can wait a little longer to water.
Always put nutrients in your water... Every single time. The runoff will prevent nutrient buildup and as long as it doesn't dry your nutrients will stay nice and balanced.
You should be ph adjust tin the feed to 5.8-6.2 before feeding.