I have also problems with my Favero pedals…
And im a bit dissapointed from their quality control…
A bit of personal History and Favero…
Back in 2018 i bought my first pair… All good except then i had battery discharging mid ride so contacted Favero… After few months we agreed to send me new spindles…
And new frustrations regarding shipping. Since there was battery included in the spindles only DHL Express as option which was super expensive with their local broker fees (this is not Favero problem and they were very very friendly and supportive). So they send them to my friend in Germany, and he bring me here (i live in non EU Country)
At the end, i was super satisfied… This made me to buy new Pedal Bodies for the new spindles, and also another Pair of Favero (i have three bikes which i ride often so my idea was to end with every bike own pair of Favero Duo)…
Then last year i bought another pair of Favero (now all of this three bikes has own pair)… Perfect…
Until in October 2021 one of the replacement Spindles started switching off mid ride 
(on this replacement spindles i have max 7500km)
I have thread about it… Favero Assioma Problem
So i thought bad luck and decide to get new pair as a replacement (because of shipping problems i had to send them again to friend in Germany, still waiting to bring them to me)
In meanwhile i realize last pair i bought in 2021 have problem with power beeing totaly off… (on this i have max 3500km)
Like 7% lower vs my other pairs Also strange left-right balance discrepance… While my left/right on other pairs are 50:50, 51:49 or similar, on this problematic pair balance is 55:45…
I done static weight test, and seem that this test is ok, dont show big weighting discrepance, but power reading is totaly off…
So i tried to adjust the power trought app (putting like about +4% in power settings), and i got pretty similar power curve to the rest (im benchmarking against Direto XR-T and other Favero Pairs)
But also even more strange left/right disbalance (i got 59:41 on last ride, reset the lap calibrated then ended with 54:46)
So in my possesion and usage i had 4 pairs (not counted the last pair which i still wait to arrive)… And on three pairs of them there was a problem Pretty bad luck, or quality control…
Last time i ended satisfied from Favero support, but still dont expect to have this problem with almost every pair i own and especially problems i have with shipping them (because of batteries in the pedals i guess)
Anyway, im doing more detailed tests now before i contact Favero Support, and maybe i’ll go this time with retailer support where i bought them, since i have very good experience with them and for me best online shop (bike24).
So will see what will end… But i feel a bit frustrated i must admit 
I expected more reliability and quality