Auto capitals when sentence ends in number?

When a sentence ends in a number followed by a full stop (period), the first letter of the following sentence is not automatically capitalized. I have the “capitalize first letter of every sentence” option ticked in auto-correct for both modifications (M) and auto-corrections while typing (T) and I can’t find any exception that would explain this. Of course in some languages, a number followed by a dot is an ordinal and you wouldn’t want automatic capitalization following it, but this is only rarely the case in English. Why isn’t every sentence being capitalized and how can I fix it? Thanks!

An AutoCorrect feature (I name it “AutoSpoil” in mind) isn’t exactly the golden egg of ArtificialIntelligence. The concept behind terms like “sentence” or “word” isn’t simple enough for a tool of that kind.
A solution you might like would need to be locale dependent, wouldn’t it? Bad idea, imo.
I would suggest to use the shift key.
If AutoCorrect should manage it, a reasonable approach might be to never use a simple space in front of a decimal number ending a sentence, but a non-breaking space (U+00A0). That’s recommendable concerning the automatic line-wrapping anyway. Then the construct consisting of an ordinary word, the NB space, and the number could be recognized as a “complex word”, and trigger the automatic capitaization.
However, that’s not the way current LibO handles it.

What I’m looking for is an option that automatically capitalizes the first letter following a dot and a space. On the very rare occasions that isn’t correct for me, I’ll use the backspace key!

Actually, I think the problem is slightly different: How to tell autocorrect to assume that a full stop followed by one or two spaces is the end of a sentence, regardless of what came before?

I think I roughly understood what you wanted. Unfortunately I cannot offer a solution - except by a lot of programming, probably. I won’t do. My comment above tried to explain the context I would consider relevant.
If you want to insist: File a bug (type enhancement request) to https://bugs.documentfoundation.org/ .

Thanks, I’m not sure I’d consider it a bug exactly – it’s just the way it is! Shift key is the least hassle way of doing it in the absence of an autocorrect feature.

The “bugs” system also accepts post not reporting a bug, but suggesting an enhancement.
See also my answer.
You may have already cheked which items of the submenu >Format>Text might be useful for you.

Suppose you are typing, and only notice a missing capitalization after having typed a few additional letters. This is the case where the action after the event is rather complicated : Ctrl+Left, Shift+Right, type capital letter, Ctrl+RightLeft (depending).
If you want to do this by one shortcut and without changing the view otherwise, the needed user code is simple:

Sub capThisWord(Optional pEvent)
  On Local Error Goto fail
  doc = ThisComponent
  pos = doc.CurrentSelection(0).Start
  tc = pos.Text.createTextCursorByRange(pos)
  tc.gotoStartOfWord(False)
  tc.goRight(1, True)
  repl = Ucase(tc.String)
  tc.Text.insertString(tc, repl, True)
fail:
End Sub  

The word the Sub works with is the one where the “hair” inserttion-cursor is positioned. You can simply place it in a module of your local Standard library of MyMacros and aasign it to the shortcut of your choice.

Oh, that’s actually quite useful. But the ctrl+left (etc) rather than the code. There’s a lot of unintuitive assumed knowledge in these programmes. Cheers!

Ctrl+LEFT/RIGHT is quite a common shortcut in text manipulation programs. And most of the unintuitive assumed knowledge is covered in the documentation - for example Keyboard Shortcuts

For a little interesting reading Table of keyboard shortcuts - Wikipedia

Thank you.