I have Samba (4.11.13 + git.189.e9bd318cd13-lp152.3.13.1) running on Leap 15.2
and keep getting the following error message:

Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.267674,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.271272,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.272085,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.272946,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.273663,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.274405,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.275349,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.276083,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK
Oct 10 20:34:24 server smbd[10172]: [2020/10/10 20:34:24.276802,  0]
../../source3/locking/locking.c:717(remove_share_mode_lease)
Oct 10 20:34:24 server smbd[10172]:   remove_share_mode_lease: leases_db_del
failed: NT_STATUS_OK

This occasionally interrupts the data exchange.