I agree with the others here that this issue generally points to a firewall or network-related issue.
Should you have static or strict firewall rules, this can make it difficult to keep distsrv in an appropriate range.
You may, however, force distsrv to use a specific port of your choosing with the '-p <portnumber>' argument.
First, right-click the distsrv probe in IM and select Edit.
In the ‘Arguments’ add “-p <your port number>'.
Finally, select ‘OK’ and then re-start the distsrv probe.
From now on, when the probe comes up it will be assigned to the port you indicated.
Please note that this does not work for all probes - distsrv is one of the few.