Tried reproducing using command line and below are the findings.

Created CIFS share.
Added access rule which added valid user.
stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$ manila access-allow myCIFS_Share2 user Guest
stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$ manila access-list myCIFS_Share2                                 +--------------------------------------+-------------+-----------+--------------+--------+------------+
| id                                   | access_type | access_to | access_level | state  | access_key |
+--------------------------------------+-------------+-----------+--------------+--------+------------+
| 77a7d557-cfc1-43dd-9142-4d7940bcdfcf | user        | Guest     | rw           | active | None       |
+--------------------------------------+-------------+-----------+--------------+--------+------------+

Then I added a rule which added a invalid user to see state as error for both the access rules.

stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$ manila access-allow myCIFS_Share2 user 3parbrowse
+--------------+--------------------------------------+
| Property     | Value                                |
+--------------+--------------------------------------+
| access_key   | None                                 |
| share_id     | 47610cc7-a656-4bbc-81c8-c9f14b6006b3 |
| access_type  | user                                 |
| access_to    | 3parbrowse                           |
| access_level | rw                                   |
| state        | new                                  |
| id           | b490106a-6981-47a6-8879-e0885c647069 |
+--------------+--------------------------------------+
stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$ manila access-list myCIFS_Share2
+--------------------------------------+-------------+------------+--------------+-------+------------+
| id                                   | access_type | access_to  | access_level | state | access_key |
+--------------------------------------+-------------+------------+--------------+-------+------------+
| 77a7d557-cfc1-43dd-9142-4d7940bcdfcf | user        | Guest      | rw           | error | None       |
| b490106a-6981-47a6-8879-e0885c647069 | user        | 3parbrowse | rw           | error | None       |
+--------------------------------------+-------------+------------+--------------+-------+------------+
stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$

Next I removed the access rule for invalid user.

stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$ manila access-deny myCIFS_Share2 bb0f69a4-6643-4d65-865e-cefd2d7d267c
stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$ manila access-list myCIFS_Share2                                 +--------------------------------------+-------------+-----------+--------------+--------+------------+
| id                                   | access_type | access_to | access_level | state  | access_key |
+--------------------------------------+-------------+-----------+--------------+--------+------------+
| 77a7d557-cfc1-43dd-9142-4d7940bcdfcf | user        | Guest     | rw           | active | None       |
+--------------------------------------+-------------+-----------+--------------+--------+------------+
stack@cld4b11:/opt/stack/manila/manila/share/drivers/hpe$


Just to summarize, adding access for invalid user changes the state for all the access rules.
Removing access rule for invalid user changes state back active.