I can confirm I am having the same issue.
The model is welded together with Motor6D and is animated. The parts on the model have Texture instances in them, and the texture stretches to 0,0,0 in the workspace. This stops when the textures are removed. The parts are MeshParts set to Precise render. I am able to see it locally, but other people cannot see it.
I also am experiencing this with certain swords which use Textures/Decals with welding. Haven’t really found a fix around it yet.
From testing, I can also confirm it can happen inside viewportframes aswell.
Is there any updates on the development to the fix we can expect soon? It has been over a month now since this issue has been reported.
For my games at least, I need textures and humanoids and it seems almost every model I have in-game is replicating this issue. It is causing immense frame drops in-game and in-studio whenever looked at and is extremely obstructive.
Can we expect a fix to this soon?
Thanks! 
Hi guys, the fix is on track to be released next week.
Will there be any notification or update for when this is fixed?
I’ll post here once the fix is enabled.
Alright thank you and to give a bit more context, it seems the textures and decals start doing this when there’s a humanoid applied. (Didn’t see anyone mention it occurs specifically when attached to a humanoid) https://gyazo.com/2b3d6ad43f3a432f48c07df81e1903a0
It can also happen in viewportframes and without humanoids:
The fix should be activated now, let me know if you are still experiencing the glitches.
Thanks for the update. I have just tested it on my game and players are still seeing the stretched image on the MeshPart.
EDIT: It may only be mobile phones (and potentially tablets) related cause the user who sent me the pics only saw it on him and one other user only (for sure) and both of them were mobile phone users.
Do you know if they have updated their apps?
Still going on in studio on PC https://gyazo.com/21801e50f2acf4767683449152eb9056
Not going on in game on PC
A few players reported to me this was happening to them on the X-Box app today.
The MeshParts affected were my trees with RenderFidelity set to Automatic, causing the leaves to disappear and appear wonky.
The only report I had was a user on mobile phone. I think most computer users have said it is fine.
The user has said their Roblox app was not updated, so will get them to update and try it again.
UPDATE: The problem seems to have resolved for the user once they updated their Roblox app.
I experienced an issue exactly like this but it was caused by code. I was setting my model / mesh CFrame like so:
local targetCFrame = CFrame.lookAt(positionValue, lookAtValue)
someModelOrMesh:PivotTo(targetCFrame)
There was an edge case where I would pass in the same values in the position and look at parameters in CFrame.lookAt(), this made my mesh / model sort of fold in on itself and glitch out into the skybox. Lol. Preventing the same value from being passed into CFrame.lookAt() solved this issue for me.