PBO scales with consideration of things like load, PBO parameters, internal current limits, temperatures, voltage offsets, motherboard capability, cooling capability, phase of the moon, and whether or not it "feels like it". You can't force it to boost higher.
Anyway your idle temperatures sound high, mine are in the low 30s, are you using stock cooler (Wraith Prism)? Temperatures being too high will prevent PBO from boosting much at all.
And changing the CPU ratio is an entirely different ballgame and puts the system into Manual OC mode. It will force all cores to run at that speed all the time, even if unstable or dangerous. If you DO go for manual OC, you must always set a voltage with it, leaving it on "Auto" is dangerous and the mobo can pick a voltage that is way too high. You should also not start with 45. Maybe try something safer, like 40 / 1.28v, then up the multiplier from there and see what you can get at that voltage to get a feel for it. But fix your temps first..