The R3 doesn't like tracking birds with busy backgrounds, I think the R6 on firmware 1.4 tracks better ? WDYT ?
With small birds and busy backgrounds, I'm getting better results than the R5.
I used different area selections to acquire the AF on the subject but some of them drove me mad as they didn't want to lock on the subject so I reverted to full frame acquisition, which while not perfect performed very well. WDYT ?
I am getting good results with full frame acquisition. Even better than the R5 which is really good. When it misses, I have spot focus set up on a back button to get to the right target quickly.
I find certain settings seem to reset themselves to factory settings IE. Auto card switching it turns it's self off ?? Do any guys find this happens ?
No problem with that here, but I only use CFE cards.
Cheers Joe, your findings echo mine, thank you for posting it wasn't just my imagination then ? Phew I thought it was me losing my touch lol.
I will hopefully get out soon and play around with the R3, I can live with the AF for now as the bump in high ISO quality is great for shooting in the drab UK light.
Sorry that you are having problems.
You may have misread my response. I'm getting better AF acquisition speed and stickiness with the R3 than with the R5. The R5 is no slouch, the R3 is just better for my small birds and small birds in flight, even with busy backgrounds.
I'm using the full frame acquisition mode with a back button set to point focus. I'm not knocking the R5 as I have gotten a lot of great images with it and it's AF is great. It's just that the R3 is giving me better AF on small birds both stationary and launching.
Maybe you have something in the settings that is causing a problem.
As I mentioned in earlier posts, I'm using Case Auto or Case 4 t-2, a/d+2. With the R5, I use Case Auto.
In particular, the R3 is far less likely to focus on the background than the R5 and much easier to bring back to the subject when it does. With the R5, I regularly had to use the MF ring to bring the focus back to the subject once it had gone to the background. With the R3, that has rarely been necessary. In fact, I had the R3 more than a month, shooting small birds almost every day, before I even bothered to set the MF ring to work while in AF. I'm mostly using the RF 100-500.
Do you have Switching Tracked Subjects set to 1? I used to think that setting it to 0 (Initial Priority) was the way to go, but it's not. 1 (on Subject) works better for me on the R3 and R5.
If changing those settings doesn't fix things for you, you might try resetting to default and start over with just the basic AF settings and see if that helps.
Good Luck!!!
feel free to chime in 
if your cover is the same as mine (quiet loose) it is so easy to knock off putting your camera in your bag or knock it off in general use ......... Crap design Canon !
not good Canon.