I haven't seen the led driver boards, but the flicker is either lack of amps(ma likely here), a dead diode in the supply (half wave) or lack of capacitance. I.e. the larger supplies amps, the less likely a flicker will occur, a capacitor would smooth any half wave pulses. (Some folk are more sensitive to flicker too.)
LED batches could easily throw off an extremely closely matched supply.
Not an excuse, but an explanation and a possible work around can be had from this, especially when folks pick up "mystery boxes".(a cheap grab bag offering, normally well worth it regardless of.some items. less than perfect conditions.)
Menard's in store customer service will mostly depend on an areas general attitude, like any other store. With expansion into less rural areas they are going to have issues some places, but in my experience in traveling repair and installations, Menard's wins customer service hands down. I complain at store and corporate level both in case the general manager is part of the issue via poor training or just plain apathy. This factors.can get.missed easily if the store accounting numbers are still good.
Contacting corp. level today in many companies is becoming a joke however, impossible at times...E.g. Dollar Stores offer nothing other than store.level contact, and I doubt the brass cares about even helpful info, let alone a complaint even tiny amounts of their dishwasher powder leaves dishes looking worse than water alone, because they still have it on the shelves despite evidence shown, and in store demonstration that it wont rinse off, hot or cold.