My bad, the issue is a bit different, you’re reporting 0 minutes. The fixed issue was that there was no value at all. Both were fixed by article updates.
I can only imagine that no text is being scanned and hence 0 is returned. Unfortunately it seems to be specific to your site, so a combination of themes / plugins is the most likely cause.
If you’re able to find the time to investigate what the cause is, feel free to report that on our GitHub repository (see https://www.ads-software.com/support/topic/estimated-reading-time-2/#post-13906995). We might be able to look into that if enough information is provided.