Simultaneous USB connections limitation

I get my hand on a Samsung Galaxy Tab A7 Lite LTE and I want to connect several devices to it. I use an USB Hub with 7 sensors connected to it and my app retrieve all the data. My problem is I can't connect more than 5 devices simultaneously with the samsung tab. This is odd because I have a Huawei (MediaPad M5) and I can plug it in 10 devices at least without any trouble. Unfortunately, Huawei doesn't produce GMS compatible devices anymore so I need to change my supplier brand. So my questions are: Why is this USB connections number restriction? Do you think it's a soft or hard issue? Can we find out any list of tablets with the max devices number supported? Why doesn't it show up in the technical specs ? Thanks for reading me, any help would be appreciated !