Hey there, sorry for any delays.
When your only having issues with side to side operation it's usually just a bushing or something simple causing the resistance.
First thing I would do is remove the shift knob so you can pull the console trim covering the shifter assembly and inspect the guide plate and bushing.
When you only issue is side to side movement it's usually nothing serious indicating a malfunction with the gear box itself, so i wouldn't be too concerned in that aspect.
Let me know how else i can help please.