Voicemail and Ring time before going to voicemail.

Since I changed over to an eSim I have had problems .... firstly with ring time. If I try to extend it by using **61*121*11*25# it just says invalid MMI code. I have tried various other codes but they all come back as invalid MMI code. I can live with it the way it is .... I get about 15 seconds to answer a call but it's not ideal.
However this lead me to check my voicemail outgoing message etc...... all seems to be set up and activated (I have dialed 1211 to reactivate etc) but.... when I called myself from my other phone and let it go to VM .....the line just goes dead instead of hearing the outgoing voicemail message.
I've just been on to customer service on chat and he is going to reactivate my eSim .....or at least he's sending me a new link but can take 24-48 hours which seems a bit long.
Been with Lebara for about 5 years and reluctant to leave ..... but if they can't sort this I will be off!
Sorry for the long post but anyone else had similar problems ??

Update... If I switch off my esim and call from my other phone it goes to voicemail ok. Switch the esim back on and I get ringing OK .... then silence.
No sign of the new esim which is pretty disappointing. I think I'm jumping ship. My customers getting a "blank" voicemail is no use whatsoever !!

Biglox Did you manage to solve this, i have the same problem, my esim just rings out, theres no mailbox greeting even though i have set it as active

Sadly no resolution to either problem and when I contacted customer service (several times) they are obviously just working off a scrip and have no technical knowledge whatsoever.... So if the script doesn't work they are stumped.
I have in fact left Lebara (both my phone and my son's phone and have moved over to Talkmobile... 3 x data for the same price!! Admittedly I've lost the 100 mins calls to Oz etc but I can live with that now that I can set my voicemail and ring time etc.

PeterG3 You can get a voucher if you sign up with my refferal link. https://refer.talkmobile.co.uk/malcolmm-912
Now 45gb for £6.95....they use vodaphone too. 👍