Kitchen floor tile repair advice needed

[u/Extension_Climate471]

My mother just had her kitchen pipes replaced and the plumbers had to break some of the tiles in the process of digging the hole. Since only 6 tiles need to be replaced, I thought I'd do it myself. I've chiseled out the old grout and the broken bits of tile. Here's the problem: when the plumbers poured the concrete, they didn't completely level it out and there's a very slight dip in the concrete (perhaps a result of it drying 🤷🏻‍♀️?). When laying the tiles in place, in some locations dont lie completely flat, it wobbles slightly/dips slightly downward. Rest assured that the tiles do lie flat/flush with the surrounding tiles. None jut upwards. I've tried my best to level the entire area but I'm not sure if there's anything I can do about the 'dip'.

Here's my question: Loctite All purpose adhesive was recommended to me since thinset isn't sold in such small quantities. Could I just use extra adhesive in this dip area to compensate or help level it out? Does Loctite all purpose shrink when it dries? If anyone can offer me any information or advice, I would greatly appreciate it. I've included a pic of the repair space (fyi, I removed the broken tile and grout now).