**System Information**
Operating system: Linux-5.8.0-44-generic-x86_64-with-debian-bullseye-sid 64 Bits
Graphics card: Mesa Intel(R) Xe Graphics (TGL GT2) Intel 4.6 (Core Profile) Mesa 20.2.6
**Blender Version**
Broken: version: 2.92.0, branch: master, commit date: 2021-02-24 16:25, hash: `rB02948a2cab44`
Worked: (newest version of Blender that worked as expected)
**Short description of error**
[Please fill out a short description of the error here]
Level 1. When texture painting in the 3D viewport, the image is updated, but the visible shader on the object doesn't update in cycles until switching to viewport shading and back to cycles.
It still works when switching to Eevee shading. When reloading the image in the shader image texture node, it updates in cycles, but the problem persists when the image is updated (painted on) again.
Level 2. The above bug becomes worse as follows:
In cycles the image stops updating even when switching to viewport shading and back to cycles.
(A)-When reloading the image in the shader image texture node, it updates in cycles, but any new paint on the texture in the viewport or image editor -> paint mode won't update until step A is repeated.
I do not know exactly what triggers this 2nd level bug, but it doesn't take long to show up.
I was able to repeat it just by painting and switching between Eevee and cycles using my test .blend file (attached)
**Exact steps for others to reproduce the error**
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]
1. Assign a material with an image node to an unwrapped object
2. Switch to viewport texture painting and start painting on the image in cycles shading.
3. The image updates in viewport shading, but not the visible shader on the object in cycles.
4. Switch to Eevee shading - now eveything works as expected.
5. I do not know what triggers the level 2 bug.
{F9902374}