can over watering/transplanting cause nutrient lockout/defiency?

Short answer is "no" - overwatering/transplanting cannot cause nutrient lockout or deficiency... you get these when your PH is not in a proper range (6.0-6.5)... nutrients are available to the plant only within certain PH ranges so it's essential you give both water and nutes that have been PH balanced. To check this, give your plants enough PH'd water that you get some runoff and check the PH of that runoff.... if it's not within the proper range, you'll need to do a flush (run 3x the amount of water as the size of the pot) and then let it dry out before giving it anything more. Check the PH of whatever you're giving your plants each and every time... and occasionally check the runoff.... The one tool I wish I had started out growing with is a PH pen... nothing else is as accurate and therefore nothing else is even moderately useful. I personally use an Apera - which is just as good as the "gold standard" Blue Lab but less expensive. Good luck!

Everything that crimson said is good. And right. Overwatering takes a few weeks to show. For instance I overfed 2 of my plants this week. I forgot I fed a Epsom salt the day before and ye, 9verwatered, it pissed out the end. But nothing happened, and I knew it wouldn't. I've had 1 plant be droopy. As for transplanting, well, that in itself done right gives you stronger roots. And helps against nutrient lock and defs.

plants are not overwatered in one session. a good medium shouldnt get waterlogged with a single heavy watering unless its sitting in runoff. however overwatering is a chronic problem just because you give a little too much water one time it’ll not cause overwatering symptoms. now after saying that yes overwatering causes all kinds of deficiency symptoms because it stresses the roots and drowns them. as for your solution, let them get lighter. not completely light but substantially lighter saturate the whole medium once and let it get lighter again before watering. keep repeating that.

You must, have a watering interval (LET THE SOIL DRY COMPLETELY not only roots wither, a dry soil as they will breathe and PROSPER, with excess watering some element has been absorbed more blocking other elements. AFTER THE SOIL DIES, TAKE AN EVALUATION TEST AND CHECK THE PH (I SUGGEST THAT YOU DO ACCORDING TO SOLO PH 6.5 HYDRO 5.6 SO YOU START WITH A DRY SOIL ROOTS READY TO RECEIVE WATER WITH THE CORRECT PH, YOU DON'T NEED TO NUTRITE YOUR PLANT THAT WILL BE RECOVERING.