When I flush toilet next to the bathtub it gurgles now. And out of no where the tub will not drain after a shower it takes forever to completely drain. I had this same problem a month ago. I snaked the tub 50 foot and it comes back clean, I snaked to roof vent with a 50 foot and brought back some leaves and pine needels.
The tub drained fine for a while, then had to the same problem 2 weeks later so I used a 75 foot snake and it seem fix it.

So here I am back to where I started a tub that won't drain Every drain is the house is fine except the tub . When I pop open the clean out in the front yard I have great water flow to the sewer.

Any Ideas?
Thanks

When I flush toilet next to the bathtub it gurgles now. This indicates a blocked vent. The toilet's attempting to vent through the tubs trap.
I'd give a hard look at the bathroom lavatory vent. Make sure when you reach the base of the stack that you put out 20 feet more. Good luck, Tom