Test log takes a long time to download or may not finish downloading at all, and renders incorrectly

With the failure here

https://codereview.qt-project.org/c/qt/qtdeclarative/+/421497/1#message-50b162705e0a4901fc186c9d62c1c29aaadfb45b

there is a link to the build log:

https://testresults.qt.io/coin/api/results/qt/qtdeclarative/cdf3b3f2c61777c5294aed9016f8ca3cbf04fd70/MacOSMacOS_12arm64MacOSMacOS_12arm64Clangqtci-macos-12-arm64Sccache_TestOnly/4e4492cba6224228722ab8a56230ee6f66014553/test_1657852906/log.txt.gz

This page takes ages to load, and sometimes I get this response:

Proxy Error

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /coin/api/results/qt/qtdeclarative/cdf3b3f2c61777c5294aed9016f8ca3cbf04fd70/MacOSMacOS_12arm64MacOSMacOS_12arm64Clangqtci-macos-12-arm64Sccache_TestOnly/4e4492cba6224228722ab8a56230ee6f66014553/test_1657852906/log.txt.gz.

Reason: Error reading from remote server

When it does load, I get this jumbled mess:

I'm on macOS 12.4 using Firefox 102.0.1.