JPEG Files saving at a fraction of the size they used to since updating the software today

You should always indicate the correct version of the programs you're using, as vocabulary like "the latest version" is very imprecise and is untrue at latest with the next iteration. Or, some problems are really version sensitive. You should also add the OS version you're using.

1 - I haven't changed any settings, but since the update the file size decreased dramatically.  Prior to the update the Max JPEG file size was at least 23MB, and after the update the max file size is now around 4-7MB. 

By @PamelaCorey

Some small precisions are needed here: what is the type of pictures you save here and what is the pixel size? How do you save as JPEG?

2 - the brush tool is no longer precise - it brushes outside the confines of the circle!

By @PamelaCorey

Could you help out with a screenshot?