Missing Emails

[aLang]

Since the latest version of Thunderbird, I am missing at least 2 emails the were sent to me on December 18th 2023. They appear in my Outlook account inbox but there is no sign of them arriving in my Thunderbird in box - Why.

They are not in that ghastly thread concept that means I can no longer see emails in chronological order, because they are tagged into the thread of another email. They have not gone to junk. How many more emails are missing. And all this after I recently sent another contribution to Thunderbird.

P.S. I am not very good at finding answers in FAQ's as I can never ask a question in the correct way

[aLang]

Thunderbird replied To control which emails we send you, please go to manage your subscription & notification settings or unsubscribe.  but I do not understand surely I want all emails except junk ones so why have they suddenly decided not let some through. and anyway I cant find, manage your subscriptions and wouldn't know what criteria I am supposed to chose