Hate to say it, but the long-term fix is going to be replacing the actual light fixtures with something (or a system) that has integral voltage regulators. LEDs are great, but more sensitive to the power fluctuations we see in our average power feed coming in from the city, and those bulbs just aren’t made to handle that wide swing.
When we did our site (before I retired a second time) we tried the bulbs in 1/2 the warehouse, but had the same issues. In tne end, we wound up doing a complete system swap and wiring upgrade; including work to the main feeds into the facility.
Do y’all have your own power plant?