Second beta for 2026.7.3. Contains everything from b0 (the grid export fixes for #253, #254, #278) plus:
Fixed: 3D buildings disappearing (#285). The Overpass mirror list is refreshed (a fast, stable European mirror now leads), each mirror gets a 10-second watchdog so a hung one fails over instead of stalling the load, and when every mirror is down the card now retries automatically after a few minutes instead of showing the fallback house until the page is reloaded.
Install: HACS > Helios > menu > Redownload, enable "Show beta versions", pick 2026.7.3-b1 (or grab helios.js below for manual installs), then hard-refresh your browser.