4G not consistant

I spend a bit of time on Linwood side of town Christchurch.

At excactly the same location, same weather conditions about 60 to 70% time it's on 3G

Then 30% time 4G.

I've was on 3G for first 10 minutes then it has now changed to 4G for this connection and I'm sitting in same chair.

Why so inconsistent? Other 4G areas of Christchurch it stays on 4G the whole time.

Not so good for streaming with data clock. Been with 2degrees a long time, but thinking of testing a different network slim to see if coverage better, that has slightly better data clock rates and similar prices to $19 roll over.