Render is cutting off last few seconds of video

Davinci Resolve free version 18.6.

Odd thing happening - I rendered a roughly 22 minute video, and the render finished without doing the last three seconds or so.

Render is set for entire timeline.

Why would Resolve do this? Never seen this before.

I can think of two possibilities. Is the out point of the timeline on the render page actually at the very end, or short of it by those three seconds? Do you have enough space on the destination drive for the render?

What if you add 3 seconds of Video Generator black to the timeline, and then render out the entire timeline (including the black at the end). What happens then?

What is the source material? What file format are you rendering to?

In/Out points set at the Deliver page?
Happened once to me as well...