I am not 100% positive, but it could be being caused by tannins/toxins from the wood chips basically poisoning your plant, especially if the wood chips are fresh/green and not weathered. Removing the wood chips would be my first action, but if it is tannins/toxins, it could take a few days to leach out of the soil and before your plants pick up. If using anything for a mulch around plants, dried and well aged materials are best. Your soil also seems to look rather wet, a condition amplified through the use of mulch and I would also be allowing the soil to dry reasonably before watering again, but remove the wood chips first. Wood chips will also "suck" a lot of goodness out of the soil, especially nitrogen, as they break down. Alfalfa (lucerne) meal/straw/hay is probably one of the best things to use as a mulch, it has a very high carbon/nitrogen ratio and will not "rob" anything from the soil as it breaks down. All other hays/pea straw/oat straw etc will also rob goodness from the soil as they break down, and for best results require a scattering of aged animal manure on top of the soil before laying the straw/hay down.
Hope this helps,............
Organoman.