@gabechosen15 I'm guessing you workout between night sleep and nap ka gap jo bachta hai right? Try skipping the nap and night sleeping for longer if that's feasible.
@gabechosen15 It could be a sign of cns fatigue. PPL might be too much for you. I did use to get yawning when I was doing loading-unloading job and training as well. Try a deload week and change your split or decrease total volume of PPL.
@gabechosen15 imo you are not working out hard enough. some light cardio can bring your heart rate to 120. Then working out your heart rate should be 120-150. less than that ,you are taking longer breaks. Don't think it's possible to yawn when your heart rate is 130ish. these are just my observations. I am not a certified trainer.