Steps to reproduce:
1. Create a new presentation in 4:3 format
2. Import an image
3. Put a formula under the image
4. Choose Slide->Properties...->Format and resize to 16:9
The problem is that both of these objects are now down-scaled vertically but not horizontally.
If instead, you choose to uncheck the box "fit object to paper format", then all the content at the bottom of the slide will run off the bottom of the newly formatted slide.
Why doesn't the switch to 16:9 simply widen the slide equally on both sides? It looks like the current implementation fixes width while making the height smaller.
Created attachment 156365 [details]
Test 1 ODP
Thanks for report. It's preferable to attach a sample document.
I attach some now, hope it shows.
Created attachment 156367 [details]
Test 1 compared 4-3 and 16-9
I confirm the behavior in master 6.5+.
Already seen in LO 3.6, where 4:3 and 16:9 are first available in Format-Page.
I'll set New, although this may turn out not to be a bug. Let's ask UX.
Workaround is to set Original Size.
Clearly a bug to me, and annoying for many users so at least average relevance. Wonder that we shouldn't have a duplicate for this.