Extra space on pages of MS Word doc:(

So I took my double spaced MS (for self-publishing), copied it all, and switched to 1.5 space for every page in one click.

Unfortunately now at the bottom of every page there are about 4 to 6 empty/blank sentence spaces. I can't bring the next page up to the first to try and mesh sentences and fill the last blank areas either. I don't understand why this would happen or why it won't fill in with "my work".

I performed this with my last MS a couple days ago and that one went smooth. Anyone got any helpful tips for this? What I did or how I can make it right?

Thanks for the tips. I tried the widows/orphans. It was checked for the MS. I copied the whole thing and unchecked it several times... made sure everything was unchecked... and it still wasn't fixed. I checked it back to see what would happen and it made the page space in question grow more. May be something wrong with the program I have.

Solution - I just copied the entire MS and brought it to a new .doc and made sure the widows/orphans was unchecked and that worked fine. It is back to normal now or at least to where I want it

Here's a LESSON on how to correct the issue typically.