amp-render/amp-mustache failing to render items into table

### Description

I'm currently experiencing a not dissimilar issue to that I previously reported in #35401. I half feel it may be related, but here I have a data source not rendering anything meaningful *at all*, through ```amp-render``` and an ```amp-mustache``` template.

### Reproduction Steps

The data is tabular in nature, and I'm trying to get it into rows and fields accordingly:

```

{{#people}}

{{/people}}



Name
Gender



{{name}}
{{gender}}




```

```
{
"people":[
{
"name":"Ade Hall",
"gender":"Unknown"
},
{
"name":"Agnes Hall",
"gender":"Female"
},
{
"name":"Aimee Hall",
"gender":"Female"
},
{
"name":"Alan Hall",
"gender":"Male"
},
{
"name":"Alex Hall",
"gender":"Unknown"
}
]
}
```

Expected rendered HTML should be obvious, but this is all I get:

```

Name
Gender

```

No errors or validation issues are being reported. I thought I had the JSON wrong at first, and I do feel every time I post here that it's going to be some obvious mistake of my own that I'm code-blind to, but have now been over it multiple times and can't see what's awry, so I'm quite lost as to anything but an ```amp-mustache``` issue.