Dynamic address list time out, but still visible in /ip firewall address-list

I’ve got a situation yesterday where I had to create a firewall rule to block particular traffic. I’ve put a timeout of 10 minutes. The address lists were created correctly, and the rule worked. What I noticed though is that the dynamic address lists are still visible, even though the timeout is shown as 0s! Has anyone came accross this?
Here an example:

 /ip firewall add chain=detect-ddos action=add-dst-to-address-list address-list=dynamic address-list-timeout=10m 
      log=no log-prefix=""



ip firewall address-list print
 #   LIST                                                                      ADDRESS                         TIMEOUT           
10 D dynamic                                                                  97.80.182.89                    0s                  
11 D dynamic                                                                    188.228.33.73                   0s                  
12 D dynamic                                                                  5.145.78.207                    0s                  
13 D dynamic                                                                   75.129.131.49                   0s

The only option I have is to manually remove them, but I cannot do it in ranges! And because this was a kind of a DDoS attack, the firewall rules have created a lot of dynamic address lists:

ip firewall address-list print count-only 
8882

So removing them manually, is quite unefficient…

On that machine I’m running RouterOS 6.20.

The particular issues was fixed at 6.22-6.23, I do not remember precisely.
Install MikroTik RouterOS 6.27 on your router, then address-list issue will be fixed.