Regular payments and lump sums

Hi I have a question. I have not the best understanding of mortgages.

So I have a $309K mortgage on flex rate that iv been paying for 1.5 years (20% down). Interest rates of course went up, and so did my payments. I understand that this is correct because it keeps me "on schedule" to pay my mortgage off in the agreed amount of time.

My mortgage has two different types of "privileges". I can lump sum up to 45K a year, I can also double up on any payment I want (they make it sound like a game show but it's not really fun).

Now that we are later in the 2nd year and rates were up we decided we could afford to max lump sum for the year. We did so, however I was a bit surprised my payments stayed the same since this would also effect the "schedule." But I thought we'll hey more payments more pay off faster.

But I was thinking about how our lumps go 100% to principle (yes I got that word learned), but the increase in our payments was just to cover the increase in interest so therefore must go 100% interest. So I'm thinking maybe not "mo pay mo pay down."

If we are planning to keep doing an extra 45K a year lump, should or can we be paying less each month? Would it not be better to use that on lump sums and that would keep us on schedule? Or do we owe that interest no matter what and will just end up paying it anyways?

I don't think we will be doing any doubling up on top of the lump, we aren't doing that much bank - it's just a low cost of living city and we got good jobs so we can come up with the lumps. We don't want to lock in because who knows what's next for us or for rates (I would be more mad if I originally flexed low and locked high then I'f I stayed flex and it went higher)