BSR UA25 cycling problem.

I recently acquired a BSR UA25 changer and It play's really well until the end of the last record. Sometimes it will play it, sometimes it wont? I have read online about a delay, slider arm something that sometimes sticks, But I have no clue what that part is or where it is located on these changers. The stacking arm is level when loaded. Like I mentioned earlier it will play the last record but not every time? I someone on here has a diagram or picture of where this problem lies it would be greatly appreciated. Thank you in advance.

It's extremely difficult, if not impossible, to diagnose vintage record changer problems through a web site.
Complications are age, who was in it previously, if parts are seized, damaged, bent, missing, etc.
Even online photos can't tell me what the exact problem is.
Because I can't see it in 3D, touch it, or watch the mechanism operate to determine the situation.
And I'm a highly-skilled service tech - quite familier with these machines.
I know people in my field are scarce and scattered, but it's best to locate one who knows these devices to service them.
That way, they perform properly and reliably for decades more.

No offense intended but you sound as if you don't have a clue what you are dealing with. If you are not mechanically inclined, stay away from it and let someone knowledgeable have at it. If you are so inclined, take it out of the player, put it on a stand and run it through its cycles repeatedly and study it until you understand how it operates. Get yourself a schematic. You can't identify players without a program and you can't identify parts and their function without a schematic. Then you can better explain your problem here so that we can understand what it is you are talking about. These BSR changers are, if nothing else, rugged and reliable but after so many years the lubrication has failed and they need a thorough breakdown and cleaning and lubrication to function. We can help you but your post is too vague and is lacking in pictures which help us identify what you have and where your problem may be. So step back, take a deep breath, take pictures and ...