Seeing the red animation after enabling gfx.webrender.debug.slow-frame-indicator on https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007

Profile: https://perfht.ml/2QPWA1a

Slow Frame #01 Frame 475(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 11117 - Transaction start 1812.903707, main-thread time 4.708780, full paint time 11.954625, Skipped composites 0, Composite start 1834.289648, Resource upload time 0.002301, GPU cache upload time 0.589625, Render time 8.900776, Composite time 17.524845
Slow Frame #02 Frame 473(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 9926 - Transaction start 0.180498, main-thread time 1.903161, full paint time 1641.750865, Skipped composites 0, Composite start 1644.438298, Resource upload time 0.000676, GPU cache upload time 0.285034, Render time 4.215047, Composite time 9.853450
Slow Frame #03 Frame 474(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 9830 - Transaction start 0.150888, main-thread time 1.399705, full paint time 1625.795512, Skipped composites 0, Composite start 1628.292275, Resource upload time 0.000676, GPU cache upload time 0.285034, Render time 4.215047, Composite time 9.853450
Slow Frame #04 Frame 10(moz-extension://c6fedb6b-757e-476e-a1d9-181e8c011831/popup.html) CONTENT_FRAME_TIME 9510 - Transaction start 0.037530, main-thread time 0.385463, full paint time 1576.933214, Skipped composites 0, Composite start 1579.391044, Resource upload time 0.000587, GPU cache upload time 2.823585, Render time 4.495121, Composite time 5.516107
Slow Frame #05 Frame 21(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 2453 - Transaction start 343.092294, main-thread time 31.066206, full paint time 35.447262, Skipped composites 0, Composite start 388.605910, Resource upload time 2.734596, GPU cache upload time 0.298479, Render time 13.716897, Composite time 19.410672
Slow Frame #06 Frame 30(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 939 - Transaction start 124.777227, main-thread time 16.661353, full paint time 17.880484, Skipped composites 0, Composite start 146.742694, Resource upload time 1.676954, GPU cache upload time 0.078591, Render time 7.979086, Composite time 9.108118
Slow Frame #07 Frame 32(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 795 - Transaction start 92.645178, main-thread time 8.790147, full paint time 9.746895, Skipped composites 0, Composite start 104.433441, Resource upload time 2.193853, GPU cache upload time 0.210198, Render time 16.808233, Composite time 18.298514
Slow Frame #08 Frame 27(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 657 - Transaction start 15.282063, main-thread time 17.881554, full paint time 18.895632, Skipped composites 0, Composite start 42.729296, Resource upload time 7.843920, GPU cache upload time 0.069867, Render time 62.846929, Composite time 65.926075
Slow Frame #09 Frame 31(https://www.google.com/maps/place/Apple+Fifth+Avenue/@40.7620326,-73.9791571,15z/data=!4m5!3m4!1s0x89c258f0741ceda7:0x4fd23cddb7a3d144!8m2!3d40.7635397!4d-73.9728007) CONTENT_FRAME_TIME 626 - Transaction start 57.404851, main-thread time 10.383943, full paint time 14.643280, Skipped composites 0, Composite start 84.865552, Resource upload time 1.684228, GPU cache upload time 0.069443, Render time 3.702937, Composite time 6.060796
Slow Frame #10 Frame 1(moz-extension://c6fedb6b-757e-476e-a1d9-181e8c011831/popup.html) CONTENT_FRAME_TIME 595 - Transaction start 1.570979, main-thread time 35.525069, full paint time 36.480726, Skipped composites 0, Composite start 94.587371, Resource upload time 0.000000, GPU cache upload time 0.000000, Render time 0.000000, Composite time 0.000000

Appears to run well now.