Access Token accepted with Traditional API request but Denied with Rest API

[partsynergy]

Hi! I am a noob. Using the documentation, I have succeeded to get a refresh token. I use this refresh token with 'grant_type':'refresh_token' to get an 'access_token'. 

I can use this access token with the end-point: "https://api.ebay.com/ws/api.dll" to get all active listings on User's store. However, I get Response 403 when I try to get an item with the end-point:  "https://api.ebay.com/sell/inventory/v1/inventory_item/{SKU}"

headers = {
'Content-Type': 'application/json',
'Authorization': f"Bearer {access_token}"
}

I believe this end-point does not require a payload. Thank you in advance.

[loom2room]

I have the same issue, did you find a solution?