can not access file when s3 object path has "//"

mc ls jssz/my_bucket/exp2/
[2021-06-04 10:52:59 CST]     0B /
mc ls jssz/my_bucket/exp2//
[2021-06-04 10:53:05 CST]     0B BiaoBei-Male-DB-8/
[2021-06-04 10:53:05 CST]     0B CSMSC-1.1/
[2021-06-04 10:53:05 CST]     0B ZhaiJiuJiu/

cd ${mount_point}/my_bucket/
ls -al

total 3
drwxr-x--- 1 root root 0 Jan  1  1970 BiaoBei-Male-DB-8
drwxr-x--- 1 root root 0 Jan  1  1970 CSMSC-1.1
drwxr-x--- 1 root root 0 Jan  1  1970 ZhaiJiuJiu
?????????? ? ?    ?    ?            ? exp2
drwxr-x--- 1 root root 0 Jan  1  1970 exp3
drwxr-x--- 1 root root 0 Jan  1  1970 train
drwxr-x--- 1 root root 0 Jan  1  1970 valid