The stock LPN client for Mesh SDK v4.0.0 throws NRF_MESH_EVT_SAR_FAILED when replying to a publication set message via a friend node.
All code, reproduction data and log output is here: https://github.com/siriobalmelli/nrf_mesh_4.0.0_lpn_SAR
I also tried to implement the suggested answer from this thread:
https://devzone.nordicsemi.com/f/nordic-q-a/51486/mesh-sar-time-out
... this did not work, see this commit:
Thank you.