Tell me it works..

On a quick skim, I didn't see where you said your age, but your profile says you're female.

If you are of an age/stage to have monthly menstrual cycles, a few women here have reported only seeing a new low weight once a month at a particular point in their cycle, even though that's not the most common pattern. Maybe it's your pattern?

I'd suggest continuing at least long enough on this routine that you can compare your body weight at the same relative point in at least two different menstrual cycles.

If you're perimenopausal, water weight fluctuations can be even a little weirder than that. Things tend to settle down to milder ups/downs after in menopause for a while.

If your scale weight has been literally exactly the same for 19 days (vs. simply fluctuating up and down around the same number), then try putting fresh batteries in your scale, if it runs on batteries. Some scales have a memory, may do weird things when running low. It would be highly unlikely for a person to be literally exactly the same weight for 19 straight days . . . close to impossible, I'd say.

You are non-large. For other USA-ians like myself, 166cm/65kg would approximately equate to 5'5"/143lbs in round numbers You're aiming for another 5kg of loss, which is about 11 pounds. A slow loss rate in that situation would be the most health-promoting. (For context, I'm 165cm and 59kg, so close to you in height (5'5"), near your goal weight (130.5 pounds this morning). I'm advising you to do what I would do and have done myself, not making up something that I wouldn't apply to myself.)

A good loss rate at that weight would be around a quarter kg per week, which can take weeks to show up on the scale, and then it would show up in weight trend line over the whole time, maybe not be as visible looking only at day-to-day numbers, even at 4 weeks/one cycle. Slow? Yes. Frustrating? That's an individual question. For myself, I prioritize health/thriving over fast loss.

Since your ID has been on MFP since 2015 (also when I joined), I'm going to assume you're somewhere in the age range of 30 to 50 or so. (I'm 69.) In that range, we'd expect your maintenance calorie range to be somewhere in the vicinity of 1800-2000 daily. If your 1400 calories is accurate, and assuming that's gross calorie intake - i.e., not adding exercise calories - we'd expect you to lose weight. That might be true even if adding moderate exercise calories of a couple of hundred some days.

You say you're using cups/grams to measure food. Use the scale as often as you can - it's not just more accurate, it's quicker once you know the efficiency tricks. I'd even weigh calorie-dense items that come in a package with a grams per serving number, to confirm the serving is close to the package numbers. Make sure you're logging every bite, lick, taste, cooking oil, condiment, beverage, etc. - at least for a while, until you get enough experience data to estimate your calorie needs from that experience. Don't use other people's recipe-type items in the MFP database (things like "meat lasagna", "fried eggs", "ham sandwich"). We don't know how much oil, cheese, ham, etc. those people used. Instead, log your own ingredients. If you have so-called "cheat meals" or oopsie days, log them. Check food product labels, make sure they match the entry you log. Make sure the entries for whole unlabeled foods are accurate, too, by verifying against an authoritative source the first time you log them. (Example authoritative source: https://fdc.nal.usda.gov/ .)

Yes, that may sound like a lot. It's not necessarily essential to be that detail-conscious forever, but doing it for a while will help get a personalized accurate estimate of calorie needs from your logging and weight-change experience. Doing it for a few weeks is an investment in future predictability.

Does this whole approach work? I think so. I lost around 50 pounds back in 2015-16 at age 59-60 and have stayed at a healthy weight the whole time since. I'm not only pretty old, but severely hypothyroid (medicated) and menopausal, all things that are claimed to be weight loss doom. IME, they aren't remotely close to doom. For me, they weren't even major speed bumps.

What I think is that this takes patience and persistence to succeed at. That first 4-6 weeks or so is a process of figuring out calorie needs, learning to use MFP efficiently, figuring out how to stay mostly full and happy with new positive habits while eating foods we enjoy, and that sort of thing. If you don't get the expected results right away, collect the data, make the necessary personal adjustments, keep going.

As long as you keep chipping away at it, you'll succeed. If you try extreme things, get discouraged/frustrated easily, cut calories every time the scale pauses for a few days, or other things of that sort . . . all of that increases the odds that people will give up. Keep it simple. Treat it like a fun, productive science fair experiment for grown-ups. Keep going, tweak the tactics within the manageable range. Focus on routine habits, because they're the power tool for weight management.

Success is worth the effort it takes to get there - at least that's been my experience.

Best wishes!