Are you keeping track on your calories at all or are you just going ham while “guessing” how much you’ve eaten?
With all that exercise I bet you’re taking in A LOT of calories without even thinking about it!
The whole “No need to count or plan anything just don’t eat for 18 hours lol :D” doesn’t work when you’re dealing with that much HIIT and potentially excess calories in the hundreds or even thousand.
Just keep at it, a single month is not a good indicator.
Perhaps varying your fasting periods would change things in a positive way. It sounds like you’re doing either 20/4 or 18/6 during the week and 16/8 on weekends.
I primarily do OMAD but to shake things up I’ll do a monk fast (fast from dinner until breakfast 36 hours later) periodically and then eat a high fat very low carb meal to come out of the fast.
Doing this my keytone level stays as high as the test strips will measure even hours after that meal. Ymmv of course.
Have you only recently begun the exercising? While you are building muscle your body holds on to water for repair, and water is HEAVY. You may be toning up, like you want, just retaining water.
Other than that, what everyone else said. Measure your intake. Reduce your calories some.