Why is the first load of the app on Shopify extremely slow, but it becomes fast on reload?

At first, I thought it was due to an issue in my app (Naviplus Menu Builder), but after switching to many other apps (some of which have been around for a long time), I noticed a similar issue. When I reload the browser, the issue disappears, and all apps load quickly. My app also doesn’t score low on metrics like CLS and LCP, which indicates that the slow load is not due to app performance.

See the view here: https://youtu.be/oCaVzOI0Jwk

This suggests that there may be a bug on Shopify’s end. I’ve tried debugging but couldn’t pinpoint the problem. It seems Shopify might be waiting for a certain trigger before displaying the app interface, but it’s unclear what that might be.

Do any of you experience this as well?

This is for app, not for website pls

Did you figure out why it is so slow?