I think there is something wrong with the transmission. I hear a thunk sound/feeling when shifting gears.
Hello. This is a common issue on this vehicle. If the transmission does not appear to be slipping then you either have a failing driveline coupler or a bad transmission mount. Over time both of these can rot out and allow excessive play in the driveline. I would typically get the vehicle in the air and see if there is any free play in the driveshaft or in the transmission mount and replace what is needed. If this was not something that you planned on fixing yourself, consider YourMechanic, as a certified mechanic can come to your office to diagnose the shifting sound and recommend a repair.