Push extremely slow

Hi,

about a week ago my push requests started to take a ridiculous long time, up to 2-3 minutes each time. I have worked with the same repo for five years, and never experienced anything like this. When looking at the output, it seems the most time is spent counting remote objects, whatever that means - it seems that there are about 160 000 objects that "has to" be counted. 
Nothing remarkable has happened to my repo, i.e., no significant changes in size or content.

I have updated SourceTree to the latest version, and also updated the embedded Git in it, but that didn't affect anything, as far as I can see. My operating system is Windows 10, 64 bit version, with all the latest updates installed.

Any suggestion is welcome, since this is a huge pain in the *** right now.

Regards

Fredrik

PS. The About window in SourceTree tells me the version is 3.4.8, even though that version is listed as Unreleased in the "Affects Version/s" list below.

DS.