That's pretty good work Josh. Thanks for posting the video.
The other guys touched on it and hopefully you are aware of it. It is very common for all of us to start building in 8th or quarter beat delays on our chord changes.
This is often necessary at first because we have to think about the new chord and get our fingers on to it.
This happens because of out natural tendancy to want to play the piece at full tempo.
Unfortunately the problem with this is that the more we practice like this it becomes part of the muscle memory and hard to shake off.
You have to relearn to play it now which in the long run takes more time.
You know the chords, you can pick the strings. What you need to do now is to slow it down and count it out aloud and play it through perfectly in time no matter how slow you have to go.
The speed is easy once you get the timing, and can sometimes only take minutes by doing it right. Chances are you may never get the timing by playing at speed and will frustrate you.
Put Griffs example on, slow it down if he doesn't have a slow version. Count it through and know exactly where the chord changes and notes are on the count. Everytime you get to "2" hit that chord right on 2 with no pause. You can do it, it is just a mental barrier to overcome now. Count it out aloud while you are playing the notes and chords, this is so important.
You are going well, this is just a normal part of the learning process.
