Anyways, I wish we would get more info when newer bios are released, like what changes were made, and if there are new options, explanation on what they do and how to use them.

More likely a windows update, not everything is tied to the UEFI 

Anyways, I wish we would get more info when newer bios are released, like what changes were made, and if there are new options, explanation on what they do and how to use them.

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Anybody know that answer?

UEFI/BIOS updates don't always include microcode updates, you can update one without the other. With AMD this shouldn't be an issue, this kind of problem usually only happens with intel boards that receive updates to support a new CPU generation, Sandy -> Ivy, Haswell -> Broadwell etc. If you look at boards on ASRock's website you will note all the earlier gen intel boards only have UEFI updates listed that were released after the new gen support was added. This is to help users avoid bricking their boards by rolling back partially (without restoring the old microcode). 

As I said, AMD doesn't usually suffer from this issue as much. Personally I tend to prefer not rolling back a version number (v5.XX -> v4.XX/v3.XX) The change in version number usually signifies a large change which could include a microcode update. If a system is running well and is stable I always advise against BIOS updates. AM4 boards in particular seem to be more prone to bad flashes for some reason, you can see this on all the motherboard manufacturer forums, some quirk of the AGESA code they haven't worked out yet maybe..... 

Rule of thumb when it comes to rolling back BIOS versions, if the version number has changed, 1.XX - 2.XX, then don't do it. You are almost always safe with a rollback within a version, 1.10 -> 1.95 -> 1.20 for example. ASRock will usually pull older versions when it becomes unsafe to back flash to them however. If you really need to back flash a full version number or more then contact ASRock via support ticket and inquire, they can tell you with 100% certainty. I flash up and down all the time when writing reviews and trying to push overclocks to the limit but I tend to have backup boards on hand if something goes wrong, touch wood, it hasn't backfired on me yet.

I downgraded back to 3.30 from 4.40 with no issues although YMMV

Did you try flashing back to 3.30?

Thanks for the confirmation ZTR 

I was fairly sure that would be the case but I don't take chances with forum member's systems.

It worked for me too. 

I downgraded successfully from 4.40 to 3.30.

The update wasn't great for me. It seemed to be interfering with my Corsair Commander Pro's fan profiles. It sent one fan into full-speed state for no reason. I noticed it only after updating and haven't seen it again since downgrading.

Every chip is different, but as a general rule, it's best to try and keep the voltage as low as possible and still maintain stability, so there's no recommendation that will work in all cases.

Personally, I undervolted my Ryzen 5 1600 deliberately to keep temps in check and was able to get a stable OC (tested) to 3.7GHz at only 1.28 Volts. 

IN my case, I started with the clock speed I wanted (not pushing the chip too hard) and then backed the voltage down from the 1.35 Volt default until I hit the lowest stable voltage I could reliably achieve at that speed.

use AMD CBS. asrock mode is super buggy in the new bios so the only way to get reliable results is with a pstate overclock in AMD CBS mode. note that this means you can't use XMP profiles and will need to set your ram timings manually unless you want to run stock ram.

this update seemed to provide a HUGE stability improvement, but at the cost of a whole new swath of bugs in the BIOS. DRAM voltage seems to reset to 1.35v at boot. this is fine for me since it suddenly seems to be stable at that voltage but YMMV.

EDIT: just noticed you were running stock, in that case it probably doesn't matter as auto settings should be the same in either mode.

i tried it. asrock OC mode is fixed now.

DRAM voltage still locked to 1.35v. anything over 1.35 won't save.

they seem to have added an option to adjust SoC voltage on the ab350 pro 4, hidden in the AMD CBS settings somewhere. it takes a VID instead of an absolute voltage (similar to pstates). there is no way to tell what this translates to in volts so i didn't touch it. default value is 0 so who knows.

i reverted back to P3.30.

once they fix DRAM voltage it'll be a solid upgrade. stability is otherwise hugely improved (for me 4ghz will now boot into windows, previously 3.9 wouldn't even post).

In CPUZ and BIOS my Ryzen is 3.6Ghz but in windows and cinebench its only 3.19ghz.

I dont want to revert 3.20 because i can now run my ram to 2800mhz