I don't think the TA reading looks right, is it 74? Is the pH 7.4? If so, what's the TA?
Power Powder Plus is Calcium Hypochlorite. With a Calcium Hardness of 390 (up 20 in a month), it's probably time to stop using Cal-Hypo. Have you found a source for bleach?
I'm confused by the CYA reading, how do you get 33? Also confused because CYA dropped while using trichlor(tabs) and dichlor(Chlor-Brite) for a month. Probably want to review the CYA measurement.
The consistent CC seems odd. Should stay about 0, maybe one drop - explained by the accuracy of the test. Do you cover the pool? Maybe rushing through the FC test? Maybe CYA is a good bit higher than 33 and FC of 4.5 isn't enough?
I my experience, hydroflatus causes only giggles in well chlorinated pools - but usually only when it's observed.