Mouse delta spikes in studio when moving cursor and changing mousebehavior to lockcenter

Description: When moving your cursor in studio in a playtest and enabling shift lock, occasionally your camera goes crazy. Investigating it further, it seems that the delta of the mouse is counting the mouse being moved to the center of the screen as delta, but only if the mouse is moving as the mousebehavior gets set.

Where: Anywhere where you can use shiftlock. A baseplate, for instance. It only happens in studio, though.

When: I only noticed this starting about a week ago, but that’s when I started using shiftlock in my projects so it may not be accurate.

Videos & Images:

Reproduction instructions & files:
Minimal: Move your cursor somewhere offscreen before enabling shiftlock. Make sure you’re moving your cursor.
Specific: Go in third person, move your cursor somewhere near the top left corner of your screen. Proceed to smoothly drag it from the left side of your screen to the right, and enable shiftlock about halfway through. The further away from the center of the screen your mouse is, the higher the delta is. Finally, as stated earlier, this bug only seems to occur in studio.
Consistent: It seems to happen about ~70% of the time.

Place file:
Baseplate.rbxl (36.6 KB)

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We’ve filled a ticket into our internal database for this issue, and we will update you when we have further information.

Thanks for the report!

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I was not able to reproduce the issue, most likely because my DPI is 96. However, I realized I cannot enable mouselock at all in the local test server (accessed through the “Test” tab), on the local player session. The mouse does not lock to the center of the screen.

By “Playtest”, I’m referring to clicking “play” in studio rather than doing a local server test. I’m not sure whether or not this issue persists in a local server test- I haven’t tested.

Your shiftlock option may be set to false in the settings. Make sure to enable it first. This issue occurs regardless of what source sets mousebehavior to lockcenter, but I find it most obvious when using shiftlock.

Yes, the mouselock is enabled. Here’s a video demonstrating how mouselock does not work in studio:
robloxapp-20221228-0022034.wmv (1.3 MB)

Very strange. Might be a separate bug.