@swan617 Is your nutrition up to snuff? Would recommend a good whey protein shake w/5g creatine immediately following workouts to help recovery and also make sure your protein intake is high (at least .7g/lb of bodyweight but even 1g per lb is a great target). Make sure magnesium/zinc/vitamin D and healthy dietary fat requirements are being met as these are necessary for maintaining adequate hormone levels..
Also how is your sleep?
A bit of DOMs/tightness and slight fatigue is normal the day after a hard workout but if you are staying that way for 3-4 days and not fully recovered before the next workout its too high of a load or something is missing in nutrition or sleep. Continuing down this path will lead to eventual injury or you will lose gains.
I was lifting a split routine every other day immediately following my 10K run and regardless of eating ~4500 calories wasnt gaining weight- way too much cortisol was keeping me catabolic- bad sleep, fatigue, etc... Months on end of eating stupid amounts of food and my weight would not budge above 150lbs- I got pretty shredded, but wasn't building muscle.
Just changed my routine to a full body 3x a week and then running 5K after lifting weights, as opposed to running 10K before lifting weights every single workout. Already feel the difference- better sleep and have gained a couple lbs/pump feels better post workout. Also feel better focus and attention span at work, not so drained during the day.
Testing yourself once in a while/maxing out is good but doing it as your regular routine can end up being counter productive and cause you to lose gains.
