On macOS 11 copyfile API called from EndpointSecurity open auth callback results in deadlock on network shares

Hi,
Our product in some cases requires taking snapshot of files being opened (especially in write mode).
With endpoint security we are observing deadlock on macOS 11

• open a file from smb share using Finder

• in application, in open auth callback use copyfile api with COPYFILE_ALL flag

this copyfile api is stuck until the open auth callback is not responded to.
spindump shows copyfile stuck in kernel in smbfs stack.

copyfile with COPYFILE_METADATA i.e. just metadata seems to work fine.

we are seeing more such issues on smb/nfs network shares. The same code works well on macOS 10.15.

Is anyone else seeing similar issues?
Are there significant changes in network shares in macOS 11?

Thanks.