I strongly suspect there is no quick fix - and I equally suspect you already know that.
Just do it again next week etc. Expect to go forward and occasionally backwards in your max-lifts; but also expect it to have definite positive trend upwards.
I assume you mix it up - deadlifts, weighted walking lunges / step-ups, farmers walks and all that, right? If not, you certainly need to. Just keep at it. You have the advantage of experience (as do I, sadly...) - us old bastards can be patient...sometimes. This is a good one to be patient with.
Have faith; and a Happy New Year too!