My experience with FP4 says there is definitely a need for reciprocity adjustment for measured exposure times of > 1 second.
If you exposed a measured time of 30 seconds at 30 seconds I am not sure anything you with development will do any good.

Here is my notes, I use the same times for FP4 and HP5.

Measured New
1 2
2 4
3 6
4 9
5 12
10 32
15 57
20 01:26
25 01:59
30 02:30
60 06:50
120 18:40

The first column is measured time in seconds, the second column is the time to use in minutes:seconds.

You should try Fuji Acros sometime as it does not need any reciprocity for times up to about 120 seconds.