Hi Michael,
If you’re still encountering this issue we would be happy to investigate and troubleshoot.
Our teams just released a new stable build of Axure RP 10 so as a first step, so can you please try updating to build 10.0.0.3893 to see if that helps? You can complete this update by opening Axure RP and following the menu path: “Help > Check for Updates”, or you can download it from: axure.com/update.
If that doesn’t help, can you send over any screenshots or recordings so we can better visualize what may be going on? You also mentioned it only happens with certain projects so if possible, can you send us your .rp file so we can take a look? Feel free to email us at support@axue.com if you prefer.