Staying outside Belgium with c residence card

Helpful info: https://stad.gent/en/migration/leaving-belgium

Summary:

Less than 3 months abroad: You do not have to report your departure and return.

Please note! If you are not an EU citizen and you have an expired residence card, you risk not being allowed to re-enter Belgium.

Does your residence card expire during your absence in Belgium? Renew your residence card before your departure!

More than 3 months and up to 1 year abroad:  You must report your absence to the municipality before departure.

If you want to leave for more than 3 months, do inform your commune and follow their instructions to register your absence.

Thanks for your reply what happens is I stay for 5months and when l was coming in  was stop by immigration but the later allow me in so l was wondering why l should be ask since I didn't exceed 6month .so what do you think please let me know hope l won't be given a fine