Wireless Joint

Recently purchased a Microhard Bullet cat12 and still learning about how to use it. I had been using a Mofi4500, connected to an outside antenna which is 2 grid type antennas mounted on a 20 ft pole. The Mofi4500 would usually do from 35 to 40 mbps download.
When I got the Microhard and connected it to the same outside antenna it started out with 100 to 110 mbps download and was soon giving me 135 to 140 mbps download. I was of course amazed and pleased. After about a week the Microhard dropped off to 80 to 90 mbps download.
I am looking for some information on how to set up the Microhard. I am using AT&T service (strongest in my area) I am in very rural southeast Arizona. I am getting signals from two cell towers...the strongest one is 2 miles from me...no line of sight. The other tower is just under 7 miles from me and no line of sight.
This is new to me so many questions. When I am in the Microhard interface on my computer and looking at the page for WWAN>Settings......which is best, to enable both sim cards or set for just one sim card....i.e., will enabling both sim cards maybe give me faster download speeds or no difference?
some of the default settings....carrier status>enable.......ip passthrough>disable
sim card 1 settings.....data roaming>disable.........carrier operator>auto
technologies mode>auto............sim type>auto detect
network...PDP type>IPV4 and IPV6.......................use carrier DNS>enable
default route> yes.........................DNS passthrough>disable

I know these are a lot of questions........are these listed defaults the best settings or should some of them be changed

any help is really appreciated

I have never heard of Microhard units. Sounds Macro-Hard <yuk yuk - knee slap>

What did Microhard tell you? Or the place you purchased it?

What does the interface look like? Can you upload some screenshots for us?

Do you know exactly what modem is inside? Their website doesn't say.

Generally in openWRT based firwmares you only really need the time properly set, the APN to be correct, and depending on the carrier and plan used the TTL set.

If you started off with great speeds and then its tapered off, it sounds like your being network managed. Aka: getting dropped lower and lower on the priority for your tower. Does the speed get lower during prime time and higher during off times (early and late)?

Unless you have a static IP and sometimes one other dealio, the passthrough ip wont work anyway.
I would leave roaming turned on if it were me, but it's not a deal breaker.

I always turn off SIM auto detect, I like no variability myself and I don't swap SIMs back and forth. Though I do see the value when needed.

Here are some screen shots of the Microhard Billet interface. i also run 3 speed tests back to back. This test was with the Bullet connected to my secondary outside antenna. Is a pair of Yagis mounted on a 20 ft pole and pointed towards a cell tower just under 7 miles from me. The speed tests were done just after 12:00 noon

Based on your modem IMEI, it has a Quectel EM12G, or EG12G, modem inside. If there is a modem AT Command terminal, you can send commands to turn some features on and off, but honestly it looks like your firmware there might be doing just fine.

I'm not familiar with the webUI there, but it is fairly detailed in settings.

Honestly your speeds will vary all the time, you will never get them to be consistent with cellular. It all depends on tower load, traffic routing, etc.

What has Microhard told you?

So far customer service from Microhard has not been good at all. When I first got the router I had a question so sent a question to their customer support...took them a week to answer. At least a week ago I sent questions to them, similar to my questions on here. Have not heard anything from them...that is why I turned to you people on here.
I do appreciate your information on here.....will continue to experiment with the Bullet.
thanks again

I HATE when companies take your cash and bail on support. Crappy support is better than none at all. Some companies though. dang.

Are your signal levels varying at all? What is your signal to noise ratio (SINR)?