I ran a standard query, ancestor report to get an Ahnentafel list. The result is better than anticipated, except for a few blanks instead of numbers at various places in the Ahnentafel column. The majority of blanks are ancestors who are at the beginning of their line (no parents). There are a few, though, who have parents with Ahnentafel numbers, but I don't see a pattern with them.
The "blanked" ancestors are assigned to the correct generation, but they are skipped over in the Ahnentafel numbering scheme.
I'm running fh on a MacBook Pro (Big Sur) with Crossover. I suppose the missing numbers could be another Mac/Crossover glitch.