Audacity only exported the first 30 or 45 seconds of each recording

I have used Audacity for many years so I think I know my way around it! Yesterday I used Audacity to record all 40 of my voice links for next week’s radio shows. Each link was a separate recording (a separate opening of Audacity) and a separate export. Everything looked fine at the time. Afterwards I noticed that 8 of those links were truncated. When I investigated, I found that 6 of them were truncated at precisely 45 seconds and 2 of them were truncated at precisely 30 seconds. I have absolutely no idea why that could have happened but clearly Audacity decided to only export the first 30 or 45 seconds of some (but not all) of them. I tried to replicate it today to no avail. Before you say it, no I don’t have a disk space problem. I recently upgraded to Windows 11, that’s the only change after many successful years with Audacity. Any ideas! Thanks in advance