Unable to save build (PoB is using / instead of \ before the filename)

Check version

• I'm running the latest version of Path of Building and I've verified this by checking the changelog

Check for duplicates

• I've checked for duplicate issues by using the search function of the issue tracker

What is the expected behaviour/value?

After importing a Pastebin URL into a new build, I should be able to save/save as the build.

What is the actual behaviour/value?

After clicking the save/saveas button and entering a filename, I get the following error:

Couldn't save the build file:
C:\Users\smoker\Dropbox\Home\Games\Path of Exile\Character Builds/tempi.xml
Make sure the save folder exists and is writeable.

How to reproduce the issue

• Import a pastbin URL into a new build (I'm using https://pastebin.com/qMmKksb6)
• Click either the Save or SaveAs button at the top of PoB
• Enter a filename (I'm using "temp")
• Click the Save button

Character build code

https://pastebin.com/qMmKksb6

Screenshots

https://imgur.com/a/Q9WbKcK

No source file or test is named. Reproduce the Pastebin import, then try Save and Save As on Windows and trace where the build filename is combined with the save folder. Done means an imported build saves successfully with consistent Windows path separators.