Can't activate more than 9 tunnel entries

The Tunnel Server page allows you to configure credentials for up to 10 clients, but you cannot enable more than 9 at once. If you try to enable all 10, the 10th one is written to /etc/config/vtun with "option enabled '0'" regardless of the state of the "Enabled?" checkbox.

For example, if you have client_0 through client_4 and client_6 through client_9 enabled, all is well, but as soon as you enable client_5, client_9 will become disabled. Also, this behavior is not directly tied to the 10-client limit. If I modify /www/cgi-bin/vpn to allow, say, 20 entries, I can still only enable 9 of them.

I am currently experiencing this problem on a GL-AR750 running AREDN 3.20.3.1, but I have seen the same behavior on other hardware as far back as 3.16.something.

Thanks,
- Paul, K3PGM