I had some of that too though, that's kinda the idea. I found carby foods were most consistently weight adding, while meaty and fatty not so much.

I recall all you can eat bbqs actually resulting in weight loss the following day. But if I had a bowl of rice with them, I'd have the weight gain I feared. Moderate portions of Indian takeaway curries with Naan could keep my weight up for a few days.

That's not something I'd expect from pure calorie counting, nor do I understand what's actually going on or if it's good or bad etc. But it seemed useful to be aware of

On a day-to-day basis, weight measurement changes are dominated by changes in retained water. This will certainly correlate with daily food choices, but does not really reflect meaningful changes in body composition. Average your measurements over something like a week in order to gauge actual progress.

Carbs increase insulin more than fat or protein. Insulin is a fat storage hormone, so having carbs with your meals means you’re likely going to store more of the calories you consumed as fat.