Wendler 5/3/1 Stagnation

Guys,
I have been utilizing the forum for great advice for awhile. Great site!
I am 44 and got back into lifting 1 year ago. I have back issues but am managing through them.

My question: When do I switch exercises in Wendler 5/3/1 and how do I switch them to keep adding progress.
My current lifts are BP 275 or 225 X13, DL =320, OP 185X3, SQ 300x1.
My progress has stalled. I have been running Wendler 531 about 12 months.

Do I change the lifts, change to stronglifts 5X5, do Madcow, or change something in Wendler 5/3/1.

Thanks in advance for any objective advice.

Look into Beyond 5/3/1
In reality …what do you mean by stalled? What has your progress been since you started it?