System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 466.27
Blender Version
Broken: version: 2.93.0, branch: master, commit date: 2021-06-02 11:21, hash: rB84da05a8b806
Short description of error
Attribute Proximity node doesn't seem to work correctly when working with modifier stacks on top of geo nodes. The node will stop working upon adding a new modifier however it will work correctly if there is an empty Attribute Proximity node fed with Geometry input on the side not connected to the Geo Nodes output. Proximity is being written to a vertex group called "Displace"
Screenshots -
Example Blend file -

