[Evolution] Reply often loses a chunk of the mail trail

[Louis van Dyk <louis qdcec co za>]

Hi

I'm running evolution-3.38.4-1.fc33.x86_64 on Fedora 33.

A few times when I reply to a mail thread, I've noticed that the mail
trail is dropped, keeping only one or two messages from it.  In the
past I'd never seen this happen (i.e. the Fedora 32 days).

I can't recall the specifics of the last time it happened, but then I
had it happen today in a thread. 

I'd received mails from Office 365 users, and had replied to them.  In
the message I replied to there were two prior emails in the thread,
hence there were now three.  I hadn't had a response to the mail, so I
went to sent items, opened the mail I had sent, and hit Group Reply. 
Everything under my previous reply was gone.  In other words, my old
reply plus the new one were there.  The Office 365 messages prior to
that were all dropped.

Why could this be happening, and how can I stop this from happening in
future?

Regards
Louis