It's how romance manga usually are after first few chapters.
Have you read Rent-a-Girlfriend? Pacing is much slower there. And half of text is reserved for MC's unnecessary/repetetive thoughts.
Well, the opening chapters definitely set up strong because of their length. Chapter 1 opened with 70 pages. From chapter 2 to 5 was 48, 32, 22, 30. After that they've been between 20-22. Of course, that is to keep in mind to also out the couple pages that follow the actual end of the chapter. So things are able to "accelerate" to a certain point, and then the brakes are applied.