Anyone else noticing speed decrease mid-month until 1st of next month ?

[Dipro]

I have noted a strange occurrence mid-month on my Uncapped LTE speeds. Last month and this month already, the speed suddenly drops from 65mb down to between 7mb and 15mb. On the 1st of the month, it suddenly shoots back up to 65mb. Now, you assume it's throttling owing to data usage, but as I have been travelling, my data usage is very low. I have only used 87GB so far this month (Netflix / HBO / Hulu streaming only). See pics of speed tests below. I thought it might be coincidence last month (the huge jump back to full speed on the 1st) but as it is happening again, it can't just be a coincidence

Thoughts ?

 

[Saba'a]

Just dead since yesterday yet I have 210Gb left?

 

[Dipro]

OK, I appear to have found the problem. I am swapping Cell Towers.

16906250 is the slow one
16906240 is the fast one

Guess, it hops the tower and then there is a slower connection as per the other threads.

 

[Saba'a]

Just dead since yesterday yet I have 210Gb left?

Back again at 40mbps