Questions about Teltonika TRB140

I have a similar problem as the previous comment. I get no more than 59/47 with this device. With the same network on my smartphone (same time, same place), I get 170/50. I think this device is limited in speed which is very disappointing.

Can the unit also be connected to a 12V charge controller? According to the description, the unit has a wide supply range of 9-30V ?

I bought the TRB140 some time ago but put it aside because of the poor traffic. Recently, our UPC amplifier failed and we had no internet for 2 days. That's when I put the thing back into operation. I installed it in the attic. I have a Delock LTE antenna with 5 dBi (https://www.digitec.ch/de/s1/product/delock-lte-antenne-ltehspagsm-antenne-netzwerk-zubehoer-12301934) on it instead of the original antenna that came with it. In the speed test, I have traffic averaging 10 Mbps down and 15 Mbps up. In the same place as the antenna, I tested with my smartphone and got values of over 50 Mbps down. I tested with www.speedtest.ch and on the smartphone with the corresponding app from www.speedtest.ch. I have a Swisscom SIM without 5G (Huawei Mate 10), the SIM in the TRB 140 I ordered as a second SIM card from my Swisscom subscription (5.-/per month) should have the same speed as my SIM in the smartphone. What is the reason for this? Is the Delock antenna so much worse than the mobile antenna in my Huawei? Or is it due to a setting? It would be great to get bessen traffic with the TRB140. Thanks for your help

When I ordered this product, a SIM card was offered free of charge. I can surf without any problems, but I cannot set up a VPN tunnel. I suspect that this is due to the subscription because I get a WAN address in the 10.xxx.xxx.xxx/32 network (using WhatsismyIPAddress I see a public IP). Trying with a second SIM has given the same result. I have read that such VPN connections with so-called "shared IP" addresses do not work. Does anyone know if it would be possible to get a subscription that assigns a dynamic public address and then work with DDNS to create a VPN tunnel? (We are talking about private trials here. I don't want to go the way with a fixed public IP). Thanks for any suggestions!