Fixed
Every page scrolled sideways on a phone.
At 390px the header's right-hand item row — messages, notifications, fullscreen, user menu — is a few pixels wider than the viewport at Bootstrap's default 1rem nav-link padding. document.scrollWidth measured 412 against a 390 clientWidth on all 90 demo pages: a horizontal scrollbar on every screen, on every AdminLTE 4 page.
Below sm the header now halves --bs-navbar-nav-link-padding-x. From sm up nothing changes — the user menu keeps its 182px width and its label. Measured 412/390 before and 390/390 after; desktop unaffected.
If you check this yourself: compare scrollWidth with clientWidth, not window.innerWidth. The layout viewport widens to match the overflow, so the innerWidth comparison silently passes — which is how this survived this long.
npm install admin-lte@4.8.3Full notes: CHANGELOG
Full Changelog: v4.8.2...v4.8.3