The Libre has a tendency to read lower, so as
@Antje77 has said, do check it. But if you are going low at night, it's either your last bolus dose is too high and some of your bolus insulin is hitting you later as insulin can work up to 6 hours. Or your basic basal dosing is too high and when you are not eating or snacking while sleeping at night you are dropping too low.
Having to eat means you are getting too much insulin than you need. Eating and it still going off means the same thing.
If it's a bolus problem; Taking less insulin, changing your I/C ratio at night, many of us need a different ratio at different times of day. Eating and taking your last bolus earlier so it is out of your system by night when you go to bed can help, but if it's too high of a dose you will still have the same issue, just earlier. But at least you might get sleep while you try adjustments.
But if it's your basal rate, it needs to be lowered. If your basal is off, it can also affect all your dosing. You can try some basal testing to see if it's your basal rate.
Keep in mind, our insulin needs can always vary unfortunately. Life, events, weather, stress etc can affect our needs. Activity, maybe more activity with an 8 month old or a change of eating patterns, can certainly affect insulin needs.
Basal testing is actually pretty simple. But most people with T1D are not taught how to do it. It's a concrete way to figure out if...