# Troubleshooting Lift & Learn

> Diagnose and resolve common Lift & Learn issues with the Nexmosphere sensor, NEXMO tag matching, product details, compare mode, and RFID interference.

## Lifting a product doesn't change the screen

The screen only reacts to lift events from the Nexmosphere sensor picked in the Lift & Learn settings, so check the sensor connection first.

1. Check that **Peripherals** → **Nexmo Sensor** is set in the Lift & Learn settings. If there is no sensor to pick, the Nexmosphere edge app has not found the controller yet
2. Check that the **nexmo-edge** installation is connected to the same device as Lift & Learn
3. Check that the **XN-185 controller** is connected to the device by USB. The edge app looks for the controller every 30 seconds, so wait a minute after reconnecting it
4. Check that the **antenna**, **driver**, and **controller** cables are connected securely
5. Put the product back on its position for a few seconds, then lift it again. The screen only reacts to a product that the sensor has first seen resting on an antenna

See [Install and configure Nexmosphere peripheral](https://learn.phygrid.com/lift-and-learn/install-and-configure-nexmosphere-peripheral/) for the full setup.

## The screen shows "Product Not Found" when a product is lifted

The app turns the sticker number into `NEXMO-{number}` and looks for a product in the **Product List** with exactly that value in its **EAN** field.

1. Tap **Please notify staff** on the screen to see the tag that was read, for example `Invalid Tag/Ean: NEXMO-3`
2. Check that the product with that sticker is added under **Products** → **Product List** in the Lift & Learn settings
3. Check that the product's **EAN** field in **Content** → **Products** is written exactly as `NEXMO-3`: uppercase, with a hyphen, and without leading zeros. `NEXMO-03` doesn't match
4. If you changed the **EAN** after adding the product, remove and re-add the product in the **Product List**, then save the settings
5. If the screen shows "Loading product data..." first, check that the device is online. The app loads product data from PhyGrid when it starts

See [Integrate your product catalogue for Lift & Learn](https://learn.phygrid.com/lift-and-learn/integrate-your-product-catalog-for-lift-and-learn/) for how to set the **EAN** field.

## The wrong product is shown

If more than one product in the **Product List** has the same `NEXMO-{number}`, the screen always shows the first one.

1. Check that the sticker under the product has the number you set in that product's **EAN** field
2. Check that each `NEXMO-{number}` value is used on only one product in **Content** → **Products**
3. Check the other variants of the product, such as other sizes or colours. Lift & Learn reads the **EAN** values of all variants, so a `NEXMO-{number}` on another variant also points to this product

## The product name, description, price, or images are missing

The product details screen shows the product texts in the installation's default language and leaves out any field the product doesn't have.

1. Check that the language enabled under **Multi-language support** (see [Glossary](https://learn.phygrid.com/glossary/#multi-language-support)) matches the language of the product texts in **Content** → **Products**
2. Check that the product has a **Product Title**, **Description**, and **Short description** in that language
3. Check that the product has a **Price** with a currency. Promotional prices are shown next to the standard price
4. Check that the product's **Media** gallery has at least one active image
5. After updating the product, remove and re-add it in the **Product List** so Lift & Learn picks up the changes

## Lifting two products doesn't show the comparison

1. Check that **Screens** → **Mode** is set to **Compare**. In **Standard** mode only the last lifted product is shown
2. Check that both products are lifted at the same time. With only one product lifted, the screen shows that product on its own
3. If one side shows "Product Not Found", check that product as described in the section above

## The screen changes on its own or stays on a product after it is put back

Both are usually caused by an unstable RFID signal. The same cause shows up in analytics as many consecutive lifts on the same product.

1. Check for **RFID interference:** make sure no metal objects are placed near the RFID stickers or the antennas
2. Check that each product sits flat in its position, with its sticker directly above its antenna beneath the shelf
3. If the screen switches between products when shoppers move them quickly, raise **Advanced Settings** → **Lift Debounce (ms)**
4. Check that **Advanced Settings** → **Idle Timeout** → **Enabled** is on, so the screen returns to the idle screen after **Timeout (ms)** even when a product is not put back