Insights for Frontend Dashboard not showing data

### Self-Hosted Version

Sentry 26.3.1 c3b216e

### CPU Architecture

x86_64

### Docker Version

Docker version 28.1.1, build 4eba377

### Docker Compose Version

Docker Compose version v2.35.1

### Machine Specification

- [x] My system meets the minimum system requirements of Sentry

### Installation Type

Upgrade from 26.2.1 to 26.3.1

### Steps to Reproduce

1. Navigate to a dashboard using the Frontend Template
2. Observe no data for a number of the widgets (Overall LCP, Overall FCP, Overall CLS, Overall FID, Layout Shift Over Time, Page Load Over Time, Slowest Pageloads)

### Expected Result

Numbers in the Overall LCP, Overall FCP, Overall CLS, Overall FID widgets and data in the Layout Shift Over Time, Page Load Over Time, Slowest Pageloads widgets
See screenshot below.

### Actual Result

0s and flat line 0 graphs

### Event ID

_No response_

Reproduce the Frontend Template dashboard after upgrading from Sentry 26.2.1 to 26.3.1 using the reported self-hosted Docker setup, then trace the requests behind the empty widgets. Compare the Overall LCP, FCP, CLS, and FID values with the Layout Shift Over Time, Page Load Over Time, and Slowest Pageloads data; done means these widgets display the expected metrics instead of zeroes or flat lines.

Written by the indexing model from the issue text.