Word template problems

[AlexRagen]

I am on an M1 Mac. In my Word doc Heading 1 and Heading 2 are numbered correctly according to the hierarchy. But Heading 3 is not. Instead of something like "1.2.3 Heading 3", I get "1 Heading 3", "2 Heading 3" etc. throughout the doc. So I modify the Heading 3 style and fix the numbering, save the doc and the template, but when I open the doc again the problem is back.
Has anybody got an idea of how I can fix this problem? Thanks.

[#2]

Hello AlexRagen,
just from the description I can say that "Heading 3" will show in styles as a name of the style in a document where it is not used. "1 Heading 3", "2 Heading 3" shows when the style is used and the numbering is applied. But without a screenshot this is just guessing.
Is your issue with style, numbering, Multilevel list? Can you give us some screen shots, pls?

[#3]

@Lenka_Kerumova First of all, thanks for your reply. The issue was with numbering. I say "was" because the day after I posted, the problem vanished, just like that. It's like when the washing machine breaks and you spend all day waiting for the repairman and when he comes the washing machine starts working again just fine even though you did NOTHING different. That's exactly what happened with my Word problem.

Or maybe you magically fixed it with what Einstein called "weird action at a distance". Who knows?

Anyway, thanks again.