Why is Alto_ts415_app_BLE appearing in Bluetooth list and affecting AirPods connection?

No problem. On your iPad, go to Settings > Privacy & Security > Bluetooth. One of the apps listed there has likely added that device. When you turn off Bluetooth access for that app, then you will no longer see it as being connected to your iPad.

Once we know what app has added it, then we can help further for why it is showing up there and removing it.

• Do you have the Alto app on your iPhone? Check in your App Library by swiping all the way to the left, then swipe down to show the apps alphabetically.
• Do you have the info button next to it in the Bluetooth Settings where you can tap it to Forget the Device? If not post a screenshot of what you see.

Ok, what about other apps that have access to Bluetooth when you go to Settings > Privacy & Security > Bluetooth?

If you have multiple apps showing there, turn them off one at a time and then check the Bluetooth settings to see which one has added it. The App designation in the name indicates that an app has added the device.

The apps that are allowed to create Bluetooth connections show up here:

Settings > Privacy & Security > Bluetooth

That is launching Settings, then go to Privacy & Security as seen in your Screen Shot. After you go there, on of the options will be Bluetooth that you will need to tap to view those apps that are allowed to create Bluetooth connection. One of those apps is the likely cause. You can deny access by turning it off there and the device will be removed where you had previously seen it before.

That's bluetooth speaker system.

At some point, you paired one or more of your devices with it.

https://support.altoprofessional.com/en/support/solutions/articles/69000816748-alto-pro-ts4-series-frequently-asked-questions