Re-rendering timeline with "basic title"

Hi, whenever I open a fully rendered project in which I have inserted titles (basic title), only the clips in which the titles are present are to be re-rendered, while the rest of the timeline is ok.Is it a bug? Or are there any extra settings I need to make?
I work with Catalina 10.15.7 and FCPX 10.5
Thank you!!

Fioranelli wrote: Hi, whenever I open a fully rendered project in which I have inserted titles (basic title), only the clips in which the titles are present are to be re-rendered, while the rest of the timeline is ok.Is it a bug? Or are there any extra settings I need to make?...

IMO this is a bug. It is not limited to titles. There are various combinations of effects which can produce "lost" render files and require re-rendering. The behavior is complex and confusing, and in some cases extremely costly from a render time standpoint. 

As a rudimentary workaround you can sometimes render the timeline, re-launch FCP, then render it again and on the 2nd attempt the render files will remain more persistent. There are other cases where no render dots show (hence it should behave as if fully-rendered), yet it remains sluggish as if not rendered.

I have discussed this at length verbally and in email with Pro Apps Escalation Support, and emailed them a simple replication scenario. However they don't view it as a bug or plan to take any action. See these posts for more details:

www.fcp.co/forum/4-final-cut-pro-x-fcpx/...se-or-project-switch

www.fcp.co/forum/4-final-cut-pro-x-fcpx/...has-no-effect#110389

Ok thank you! I see the posts!