Toad is not working after

Dear all,
3 days ago we moved to the new office and have a new LAN now.
The db IP was changed and I have changed all connection properties accordantly.
I’m able to connect with sqlplus and tnsping, but Toad stuck… in all working stations.
I have re-installed Toad several times with no luck to connect again.
Any advices?
any files where Toad trace connections…?
Thank you in advance.