This was an issue sometimes with systems upgraded to 7.0.
This issue may also be in 7.1 sometimes as i have never seen any bulletin noting that this has ever been corrected.
The procedure you invoked would be your only attempt to correct the issue.
Q01086302 : Services MICS 7.0 Control Set Locks after one try
Problem description:
On upgraded running MICS7.0, the use can only toggle the ring service three
times, after that the F871/F#187 are not executed by the system. The Control
set displays the correct mode, but the system does not actually execute the 4th
command. By changing the control DN for the ring service, the fourth toggle
attempt would get executed immediately. This new control set can then toggle
three times before the system ignores the commands once again....and so on....