error ORA-28000: the account is locked

Hello,

I ran the validation procedure where I have the cursor like that:
select *
from table1@link1,
table2@link2
where ...
I got an error ORA-28000: the account is locked preceding link2.
After one hour I checked account - not locked. This part is cleared
checking the profile to the link. I am looking for any explanations of the issue why it was locked first time? I ran procedure after without resetting link2 -no errors.

Thanks in advance.