So first for some good news, assuming you are otherwise untrained (prior to starting your LP/Beginner template) you can probably gain some lean mass while losing fat mass. The smaller the deficit the easier this is to do. So basically it’s a trade-off between losing fat quicker and making some gains going a tad slower. As somone who prefers to aggressively cut weight myself, I don’t always feel more DOMS but I do feel weaker on my days where I eat very little food ~1600cals (cyclical dieting with high days and low days). The lack of food does effect recovery but if you are coming from SSLP you may not have adjusted to the (what I presume to be) increased volume of BBM templates which may take slightly longer due to the caloric restriction. This should sort itself out over time.
Regarding not losing weight, theoretically weight loss is just an Intake Vs. Expenditure problem however that is deceptively simple. Depending on how long and how aggressively you have been dieting (which at 2500 was probably not very and at 1750 is probably pretty aggressive) you will have some non-negligable metabolic adaptation, mainly in the form of Non-exercise activity thermogenesis (daily life physcial activity). Basically, when you eat less, you unconciously compensate to some degree by moving less (it seems to scale with how long you are in a caloric deficit and how large that deficit is, but I wouldn’t expect this to completely stall weightloss alone, just slow it very slightly). Usually this isn’t a big deal but since you seem to be on the ball about weighing everything out, training 3-5 days a week (as I don’t know exactly what the program you are on calls for), and haven’t reported any issues with binging, maybe this can explain a portion of the problem. Also, once you end your diet and spend some time at maintence, this negative adaptation disappears fairly quickly.
Some random things to think about:
Do you feel like you have been much less active in your daily life? specifically regarding your time outside of the gym (or if you actually have lowered your planned cardio?)
Have you started taking creatine? This leads to increased muscular water retention (which is a good thing) and can therefore mask weightloss.
Have you been taking measurements at the same time of day using the same techniques and the same equiptment?
Has your bowel movement timing changed? For example, if you started weighing yourself after voiding and now are weighing pre-void you can mask some weightloss over the short-term.
Do you feel like you are losing fat mass? This one is hard one to explain but I have noticed that when I lose weight there will be two week spans where my weight remains fairly stable then one day I “magically” lose 2lbs.
Are you using the beginner template page that tracks macros and weight? You might see a decrease in your weekly average but not as much day to day.
At 1750 calories you are probably eating at or below basal metabolic rate and therefore will lose fat mass and deplete glycogen as these are the body’s energy stores. With very aggressive weightloss (which this would definately be), comes the possiblity of retaining a non-negligable amount of bodywater that may hide some of this loss, but you are still moving towards your goal. Personally, I would aim closer to 2000-2100 calories a day on average as it should be about a pound or two a week and will help out with recovery. You can also add in some walks just to burn a few more calories a day (or trade them in for a little more food). If you choose to continue eating ~1750cals a day, when you start to feel really bad, just take 2-3 days at ~300 calories below “maintenance” with most of the additional calories being carbs. This may help increase leptin and will replenish glycogen stores therefore making you feel more satieted and less drained. It will help you feel better and let you rest some psychologically as eating at basal metabolic rate is pretty painful after a while.
TLDR
Dieting sucks, if you are tracking everything as closely as you can and not losing weight, there may be some weird confounding variables. If you go into a ~750cal deficit you should see week to week weightloss. If you don’t, just trust the process as sometimes your body does funky stuff. As long as you are in a caloric deficit you will be burning stored energy and therefore losing fat mass, even if the scale doesn’t say it.
P.S.
I’m not a doctor and this isn’t medical advice. I saw your post in nutrition and I would take Jordan’s word over mine anyday as well… he IS a Doctor and has a decade or so of experience. I’m just some random guy who spends too much time listening to M.D.s and PHDs on the internet!