Problems with buffering

We keep having problems buffering and lagging. We are using the kodi ap on a firestick.

It cant be our wifi because the wifi router and modem are within 2 ft of the firestick which is always on the flatscreen, while our laptop can be in other rooms or the same place and we can watch the exact same content without the firsetick and without kodi and we don’t have the lagging or constant buffering issues.

Sometimes we can go from one add on to another and things are better, but then sometimes not.

When I say constant, I mean as in one 25 min video might lag and or load or buffer 8 to 20 times.

Ive been deleting the kodi cache every evening and even powering off the entire system, modem, router, monitor and firestick.

Sometimes we will see improvement, sometimes it is useless. It is happening at all times of the day/night. It certainly has gotten worse as time has gone by.
I’d say we’ve had the firestick for maybe 1 year and purchased it new. It has updated several times and just updated a few days ago. But the glitching/lagging/buffering issues don’t seem to be effected.

Any idea what can be done to fix it?