This is indeed interesting and gives a first idea of what is the issue (DNSSEC retries being analyzed insufficiently). Good news is that this should indeed not have any influence at all on DNS operation, but we should still improve on handling this kind of duplicates.
Could you also quote the related lines from /var/log/pihole.log for the three entries you have pasted above?
You should be able to find them more easily using something like
grep -C 4 "dnssec-retry" /var/log/pihole.log
if my current hypothesis is correct.