Assistance integrating a Microchip MIC2288 boost converter please!

I recently recieved the 3rd (or 4th?) revision of a PCB for a project I've been working on, and am having some problems with the power/battery side that weren't there in the last revision of the board.

The problem is that I'm no longer getting proper output from the BQ24073 when powered via the battery input. If I set my bench supply to 3.8v and connect it to the pads for the battery, I get no current draw at all and checking the voltage at the output of the battery charger gives a reading of 0.06v. When I power via USB, instead of the 5.1v I expect from the MIC2288, I am getting 5.8v from the expected 4.4v input.

The last rev of the board board was using a TI BQ24073 battery charging circuit and an FS312F battery protection IC. This worked fine but at the time I didn't realize that the BQ24073 did not have a regulated output, so the supply to the microcontroller (Atmega32u4) on the board was tracking the battery voltage as it dropped. Clearly not ideal.

For the current rev I added the MIC2288 boost converter to get a 5v output from the BQ24073 to supply the rest of the board, which is very low power; around 50mA maximum draw. I left the design mostly intact, mainly just adding the MIC2288 and it's circuitry into the existing layout. For the boost controller I used:

• 10uH Cenker SMD coil, 1.092Ohm DCR, 20% tolerance.
• 4.7uF 25v ceramic input cap, X5R. Samsung CL21A475KAQNNNE.
• 22uF 6.3v ceramic output cap, X5R. Samsung CL10A226MQ8NRNC.
• MDD SS34 schottky diode. 40v, 3A.
• 5.6kOhm R1
• 1.8kOhm R2

I realize the output cap should have a higher voltage rating with the tolerance it has, and will change that for the next rev, but I don't think that is related to my issue.

There are a few other changes I made that I'll mention for completeness sake, in case I did something stupid that I thought would be fine but turns out to not be fine. The previous design had resistors and LEDs off the _CHG and _PGOOD pins of the BQ24073. I removed those and ran the lines to GPIOs on the uC for future use. I also ran a line from the BQ24073 output (which is the MIC2288 input) to an analog input on the uC, to use for checking battery charge state.

Everything works fine when powered through the BQ24073 via USB, I get the 4.4v output from the BQ24073 and I'm able to flash the uC and so forth. However, connected this way I'm getting 5.8v out of the MIC2288.

If you made it this far, thanks for taking the time. I know I overlooked something stupid again!

Relevant schematic section: https://i.imgur.com/snr6CBX.png