Did Firefox 148 or a recent update cause Windows "Efficiency Mode" to turn on? Did the update reset settings?

Just checked Task Manager in Windows 11 and noticed Firefox was running in “Efficiency mode.” I updated to version 148 recently but otherwise haven't changed any settings.

Previously, I had manually set dom.ipc.processPriorityManager.backgroundUsesEcoQoS to false in about:config to prevent Firefox from adjusting my Ethernet/network throughput, discussed in more detail in an earlier post: https://www.reddit.com/r/firefox/comments/1m82bkj/firefox_upload_speeds_are_brokencapped_anyone/

Everything was great for months, but saw that the setting had somehow reverted to true when I just checked again. Wondering whether the Firefox update reset this preference? If so, are there any other related settings affected? Or could Windows have forced the change somehow?