Hybrid XFB completely fixed the issue where the Vulkan backend was dropping frames like crazy. I can't say for sure when it happened but it's back and it happens worse and more often than ever before. Should probably test the Vulkan backend explicitly for this problem regularly because it was PERFECT as of a few weeks ago (the last build I was using was 6634). I just updated to the latest builds to try out the new QT interface and some of the new stuff and now the Vulkan backend is totally unusable again. This was a huge thorn in my side for the entire time after the Vulkan backend was introduced and when it got fixed I was so happy to finally be able to use it. This really makes me a sad panda. Any ideas on how I can help you troubleshoot this?