i have cloned litecoin wallet and edit it connect to the network we have created. I disabled checkoints, changed params and the block syncs for 32 blocks. Then i get the following error

05-26 13:07:41.876  7339  7381 W Peercom.google.bitcoin.core.VerificationException: Could not verify block a2ba184558d58648ecedCaused by: com.google.bitcoin.core.VerificationException: Unexpected change in difficulty at height 31: 1e0fd5e6 vs 1e10024c

Any ideas? The interval is indeed 16 blocks. Thanks!