@jrdemadara 

Upgrade your firmware to v5.12.9.  It seems the beta firmware is stable.

Check also the validity period of the voucher.

I hope this will help.

  @KzGx1314 my version is updated since last 2 weeks.         

  @jrdemadara Maybe you can set a Voucher with Usage of 1minutes to test it. Or check when the client connected in Authorized Clients.

  @dulu yes i already tested it several times. It's seems unstable on other device. I have 73 devices connected and more or less 40% of it has a free pass after the voucher expires.

  @jrdemadara Do these devices have anything in common? Have you confirmed in Hotspot Manager->Authorized Clients that they have reached the expiration time?

  @dulu yes i confirmed it on authorised devices. Both my oc300 and oc200 have the same problem. 

Hello  @jrdemadara,

How were you able to monitor those with free pass?

Did you check them at client if they are still connected?  

Since you set up the voucher at client usage it means that the client has the right to stop their usage.  Sample 1 hr usage voucher,  the client connects to your hotspot and use it for 30 mins then decided to stop and goes home.  After 2 hrs the client can still reconect because he still has 30 mins left which he can still use.   

  @jrdemadara 

  @KzGx1314 one of my client told me that she use the voucher a day ago non stop since we're just neighbours. He wondered why it is not expiring since it was just 2 hours per voucher. By the time i check it, that's when i discovered that it's not just him but any other device too. Other device is connected since October 7 using just 1 voucher code until i remove them from authorised clients last day and put the operation on halt. I found something on youtube about oc200 owners with the same issue. This is the link. I don't know if you can understand it but i read the same issue in comments section.

https://www.youtube.com/watch?v=n8m_kXfLSIk

  @jrdemadara 

So far in my case, it did not happen yet. My suggestion is use the voucher duration so that you won't halt your operation.  I inform your client that the voucher has no pause time. If it's 2hrs they have to utilize the hrs if not the voucher will authomatical expires after two ours.

Let's wait for the new update, hope your issue will be solved.