• Display refresh rate fallback to improve stability
• Reduced sensitivity to bed heating fluctuations on XL
• Fixes for rare BSOD crashes during filament handling

This is the release candidate for the upcoming firmware 6.2.6 for the Original Prusa MK4, MK4S, MK3.9, MK3.9S, MK3.5, MK3.5S, MINI & XL, bringing targeted stability improvements and fixes.

While the 6.2.6-alpha build included early improvements to Prusa Connect communication using websockets, these changes are not part of this release candidate. We are currently evaluating the data gathered during the alpha phase and may consider introducing the updated communication model in a future firmware release.

Automatic display refresh rate fallback

If repeated display anomalies (such as flickering) are detected, the printer now shows a prompt offering to switch to a lower display refresh rate. To ensure the message remains readable even on unstable screens, the firmware temporarily applies the lower refresh rate before showing the prompt. If the user chooses "No", the original (higher) rate is restored.

The refresh rate can also be adjusted manually at any time via Settings → Hardware → Display Refresh Speed.

Reduced modular bed temperature peak sensitivity (XL only)

On the Original Prusa XL, we've reduced the sensitivity to short-term temperature spikes on the modular bed. This should significantly reduce the occurrence of Unexpected temperature peak errors caused by nozzle heat affecting individual bed segments.
GitHub reference → #3484

Fixes for rare blue screen of death (BSOD) crashes

We have resolved several edge cases where the printer could crash into a blue error screen, most notably during filament selection and preheat operations.

Release notes: https://github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v6.2.6-RC