iPad mini screen shows white bubble-like spot on right side

I bought my ipad 4 months ago, so it is new. I don’t know how to say it, but why my ipad mini 7 screen got a white spot if i touch it on the right side? everytime i touch it, it gets white for a while like there is bubble or something, but only on the right side. I got that “white spot or something” a day after i updated it to ios 18.6. I don’t know why, but it makes me uncomfortable. The ipad is safe from the hard things, i keep my ipad on the table, and its screen never hit or dropped by anything hard because i always use case like smart folio.

[Re-Titled by Moderator]

Original Title: white spot or something like that