I have tested the portable build and it worked the same way as the installer. it worked correctly in terms of it saved I played until turn 11 then saved it and returned and it was still on turn 11, so save functioned as desired.
When the unity debug request comes up to pass the firewall do you accept it? or decline it? or just ignore it??
As that could potentially cause an issue as the game is built to debug mode(development) so I'm unsure if you decline the game might miss behave. As I can't think of any other reason why it's not working for you.
I do suggest deleting the Hope folder of the save game and installing the installer version of the game then try that hopefully you have the game as it is intended to work then.
I hope you resolve your save issue as I'm planning on expanding the game after the testing time for the game jam so it would be nice for you to still enjoy the game as it progresses.