[jggimi]

I don't know if you have proceeded as recommended in the radiusd.conf file:

######################################################################
#
#    Read "man radiusd" before editing this file.  See the section
#    titled DEBUGGING.  It outlines a method where you can quickly
#    obtain the configuration you want, without running into
#    trouble.
#
#    Run the server in debugging mode, and READ the output.
#
#        $ radiusd -X
#
#    We cannot emphasize this point strongly enough.  The vast
#    majority of problems can be solved by carefully reading the
#    debugging output, which includes warnings about common issues,
#    and suggestions for how they may be fixed.
#
#    There may be a lot of output, but look carefully for words like:
#    "warning", "error", "reject", or "failure".  The messages there
#    will usually be enough to guide you to a solution.....

There is, in that file, a discussion of thread pool management. I noticed that it states:

    #  If this limit is ever reached, clients will be LOCKED OUT......

Whatever your problem is -- thread pool consumed, or something else -- it does not appear to be OS related, based on what you've described as your problem. You might consider capturing debugging information as advised by the developers, and, if the output does not help you, you might contact the freeradius users mailing list for advice.

Good luck!