There is a severe problem with EQN and square roots

There is a severe problem with EQN and square roots. I'm
using equation 1.23.0

eqn -v
GNU eqn (groff) version 1.23.0

See example:

.SH
EQN Square Root problem
.LP
There is an example of an ugly square root in Eq. (1).
.EQ (1)
N hat sub {1, 2} = K over 2 +- sqrt { K sup 2 over 4 + { h K } over r }
.EN

and attached PDF. I've used different fonts, and the result is the same.
This is STIX

Has this been fixed in more recent versions?

Yours,

Sigfrid

-- 
Sigfrid Lundberg, Ph.D., System developer
Lund, Sweden
https://sigfrid-lundberg.se/ <http://sigfrid-lundberg.se/>