A drag failure is not always a broken mouse. The button can register normally while an application loses the held state, the pointer leaves a target, a browser extension interferes, or a wireless link drops an event. The fastest way to identify the layer is to reproduce the same movement under controlled conditions.
1. Describe the exact failure
Write down what actually happens before changing settings. Does the object never pick up, release too early, stop tracking midway, or fail only when crossing a particular region? Note whether ordinary clicks still work and whether the failure affects the left button, right button, or both. A precise symptom gives the later comparison meaning.
2. Establish an operating-system baseline
Try a simple drag on the desktop or in the file manager. Move one harmless icon or select text, then release. If the held state fails outside the browser as well, the likely causes move toward the switch, cable, receiver, battery, USB path, driver, or operating-system input layer.
If the desktop drag is reliable but one web app fails, preserve that evidence. Do not immediately reinstall a mouse driver for a problem isolated to one page.
3. Run a neutral browser comparison
Close game overlays, macro tools, remote-control software, and other tabs that capture pointer input. Open the browser mouse drag event test at https://keyboardtester.click/mouse-drag-test.php and perform ten slow drags followed by ten faster drags. Use the same button, starting area, distance, and direction.
Record four outcomes: successful pickup, continuous held state, correct movement, and clean release. One failed trial matters less than a repeatable pattern at the same point.
4. Interpret the pattern
Never starts: Confirm that a normal click registers. If clicks work but drag never begins, test another browser and inspect application-specific settings.
Starts but releases early: A worn switch, wireless dropout, cable movement, macro, or browser interruption becomes plausible. Repeat with another mouse or another connection mode if available.
Fails only at a window edge: The page or application may not handle pointer capture correctly. Keep the pointer inside the test area for a comparison run.
Fails only in one direction: Check cable drag, desk edges, sensor surface, and whether the hand is lifting the mouse during that motion.
Works in a neutral test but not in one app: Focus on that app's drag threshold, permissions, overlays, extensions, and input remapping.
5. Change one variable at a time
Use the safest order: recharge or replace the battery, move the receiver closer, try a direct USB port, remove an unpowered hub, test a plain mouse pad, close one overlay or macro utility, compare a second current browser, and finally compare another mouse. Retest the same twenty-drag sequence after every single change.