"Compression count not maximal" indicates that the compression count that is used to save space in key storage is not correct.

IF THE BLOCK IS A DATA BLOCK, that is, level zero (0), DUMP it GLO, REMOVE the records that point to it, MAP it FREE, and MUPIP LOAD the output of the DUMP GLO.

IF THE BLOCK HAS A LEVEL GREATER THAN ZERO (0), REMOVE the record and ADD it back in the same location with the same KEY=, and POINTER= or STAR.

You may also adjust the compression count using CHANGE CMPC=. Because this changes the value of all subsequent keys in the block (except the star-key), you should try this alternative only if those keys also appear incorrect.