Winbox stops downloading preferences after a second, via VPN

Hi, I just upgraded 2 RB750G’s from 4.7 to 6.12, and I am getting this behaviour:

When I connect thru LAN interfaces, winbox correctly downloads preferences and logs me in.
When I connect remotely, thru PPtP interface, winbox stops downloading preferences after at most one second. It starts downloading at full (pptp) available speed, and within a second or less, it stops for ever. So it makes it impossible to login to the router remotely.

I downgraded one of the 2 routers to latest5.xx version (5.26) by going locally to the branch and connect via LAN, and the behaviour dissappeared, so everything is back to normal with 5.26. Unfortunately I lost my second router, which is in another city!

Is there something I can do for this case?
thanks,
Dimitrios

This happen from 6.8+ RouterOS version.
Update to 6.7.
I notice that on 6.13rc20 is fixed, wait the official 6.13 version to exit out.

By.

Thank you very much, I will wait until 6.13.
best regards,
Dimitrios

I just downloaded and installed 6.13 on my RB 750G this morning and the problem still exists.
Stops for ever at downloading preferences.

Any idea on where to get 6.7? There is nothing in the downloads archive.
Dimitrios