Ex won’t pick their things up.

So I’m a little confused, me and my ex broke up a month and a half ago and she had moved out a few months before “as her way to fix the relationship” (whole other story) she has told me that she doesn’t want to lose me from her life so we can be friends in the future but we need space atm.

My issue is I still have half a room of their things boxed up and ready to go but they keep putting off picking them up, they have said it will be painful to come back here with all the memories but keep using being busy as an excuse.

The last message I mentioned about it was kinda just ignored but there are a lot of expensive and sentimental things in there.

Any advice?