Hi, got some odd behaviour which may be a setting but I can't find it. Since using Platinum any project created seems to only let me have the interface for one plugin open at a time - I open another and the one open closes automatically. Projects previously created in X3 don't do this.
Any help as it's driving me crazy please!

Pin it, in the right top corner of your plugins.

Go to Edit>preferences>Vst settings and untick "Recycle plugin window"

I recommend reading the "What's New" section of the documentation to find out about this sort of thing.

Thanks for the replies - hadn't joined the dots with what 'recycle windows' meant, plus I thought these settings were globally applied and not changed by whatever project you loaded. Anyway, working now.