Why Is

[Waddizzle]

You are not going to like my answer.  Operator Error is the problem, not the camera, not the lens.

[EDIT]. You are stuck in a rut, and need to take a critical look at how you do things.  Think outside of the box you are in.

[diverhank]

You might want to compare the pictures exif data and see what the camera is setting versus what you are setting in manual mode to be able to see what you are doing wrong.

You should post pictures that you think the camera is doing right and pictures you set that you think were blurry here.  Without having them to analyze, you are basically compelling us to conclude that it's user's error.  

Generally if there is nothing wrong with the camera and you know what you're doing, you should be able to get better pictures in M mode since you get to control everything and get the most out of the pictures.  If you don't know what you're doing, M mode might be a disaster.

[ScottyP]

50 feet or 109 feet makes no difference at all.  What was your shutter speed?  

[wq9nsc]

As other stated, compare EXIF data and see what the shutter speed and aperture differences are between your manual selection versus what the camera is selecting under program mode. 

It could be the shutter speed is too slow OR maybe you need to use the micro focus adjustment to calibrate the lens to your camera if you are shooting in manual with wide open aperture (with resultant shallow depth of field) while program AE is stepping down the aperture providing greater depth of field.  A critical error in focus adjustment will often be masked as the aperture is closed down providing greater depth of field.

If the SAME exposure triangle (shutter speed, aperture, ISO) is selected for BOTH program AE AND manual then the camera will provide the same image quality.

Rodger

[ScottyP]

The camera can do it but you are struggling. I’d suspect you were using too slow a shutter speed when in Manual. Rule of thumb would be minimum of 1/300 if your camera is full frame or 1/500 if you shoot a crop sensor. Faster shutter if subject is moving at all quickly. 

That assumes perfect form form and ideal conditions.   Try taking a shot outside in bright daylight at ISO 200 and the fastest shutter you can get.   Like 1/4000.  Should be sharp.