I'm trying to modify the ODATA query (with a Power Automate Flow for what its worth)

This works. It filters the items in a SharePoint list to only show the ones with 'cat1' in the title.

{
"host": {
    "connectionReferenceName": "shared_sharepointonline",
    "operationId": "GetItems"
},
"parameters": {
    "dataset": "https://conotoso.sharepoint.com/sites/site1",
    "table": "...",
    "$filter": "substringof('cat1', Title)"
}

}

however if I try to also filter on a lookup to another list by adding in

I get 
Action 'Get_items' failed
Bad Request
Not Valid

```{
    "host": {
        "connectionReferenceName": "shared_sharepointonline",
        "operationId": "GetItems"
    },
    "parameters": {
        "dataset": "https://conotoso.sharepoint.com/sites/site1",
        "table": "...",
        "$filter": "substringof('cat1', Title) OR Category/Title eq 'cat1'"
    }
}

Thanks P