i think this happens to everyone- some days we are stronger than others- and i think this may be even more obvious while we are beginners and still developing basic muscle strength.
i find that if i work on the pole for a few days consecutively, i become weak- but when i take a couple days off, the next time i work out i’m even stronger than before and accomplish alot more!
The effects of your workouts on your muscles mostly take place on your days off- they need rest!
Other factors that may affect how strong or weak you feel may include:
1) mood and level of motivation 2) amount of sleep or quality of sleep 3) where you are in terms of your menstrual cycle 4) what type of nutrition you’ve consumed 5) what time of the day it is (some people may feel tired after a long work day, causing them to have less energy and thus be weaker)

I’m sure there are more, this is all i could think of at the moment https://www.studioveena.com/img/smilies/icon_e_biggrin.gif