Charset problems with integrated Plogger gallery

Using the steps outlined in https://plogger.org/forum/discussion/1941/plogger-integration-for-wordpress/#Item_0 I have integrated my Plogger gallery into my blog. This all works like a charm except for a strange issue.

I’m using UTF-8 for both WordPress and Plogger and when you look at the homepage (https://www.halfje-bruin.nl/) the pages listed on the left has Australi? listed. However, when I go to the “Foto Album” link in the Pagina menu (not the top one) the text is replaced with something garbled at the end. Note that in the foto album the collection name “Australi?” is properly displayed.

I’ve removed the duplicate Content-Type header put out by Plogger but this doesn’t help.

Any suggestions as where to look for this problem?