Baby dropped 50 percentile points

[TL;DR Below]

Hello, I’ve been worrying about this for the past 2 days and seeing another post here regarding baby weights, it hit me I can turn to this community for informed experience / advice.

My baby was born at the 75th percentile, lost and regained weight appropriately at the 2 week mark, but at his 2 month check up, although he's growing, he had dropped to about the 20th percentile for weight, and from 85th percentile to 35th for height.

His doctor is unconcerned citing that my partner and I are on the smaller side (we’re not really - my husband and I are average height, and lower end of normal range in BMI). She advised we'll check measurements againat 4 months. I’m considering getting a second opinion as the significant drop and waiting another 2 months seems concerning. Baby is exclusively breastfed, and I’ve been trying unsuccessfully the past 2 days to top up with formula which he has been refusing.

TL;DR: Baby has dropped 50 percentile points in both weight and height in 2 months.

Have you had any experience with such a significant percentile drop? Could this be indicative of any issues now or in the future?

Thank you in advance!