Differences in performance of the lhu command on Rocket and spike

Type of issue: bug report
Impact: unknown
Development Phase: proposal
Other information：

Hi, I noticed a difference between Rocket and spike implementations, when executing the lhu x8,-7(x21) instruction, spike will execute normally while Rocket will report an error about not being aligned, is this a stricter measure taken by Rocket in handling alignment errors?
I hope to get your reply, please correct me if my thinking is wrong, thanks!

Start by comparing Rocket and spike behavior for the lhu x8,-7(x21) instruction, focusing on the alignment error reported by Rocket. Done means determining whether the differing behavior is expected and documenting the conclusion or identifying the implementation change needed.

Written by the indexing model from the issue text.