Pictures would certainly help, as well as all of the particulars about the flooring, how it was installed and by whom, subfloor, acclimation process, moisture readings, etc, etc. Filing the "gaps" will in most cases be like sticking your finger in a dyke.

some photos

The woo had proper moisture levels when it was installed but clearly heading milling issues. The installer installed it and has been fired and not been paid and the manufacturer Has agreed to give us extra wood for free and 50% of our money back for the faulty product. Just trying to figure out how to move forward. The moisture in the house is at 50%. We are doing A large area where we are going to rip it out completely and reinstall it from wall-to-wall... and all of the material has been in the house for over a month

If you have enough material for a remove and replace? If so, you are welcome to do it. An NWFA Certified Flooring Installer can look to see if there are areas where individual planks can be removed and replaced (patched with new planks).

Because this is 5" wide, can we assume this is "glue assisted" install (also assuming this is nail/cleat/stapled)? If there is glue, this gets harder to remove/salvage planks. Which means you need to have enough material to do a complete reinstall. You might not be able to salvage very much if this has been glued in any way.

The manufacturer came to our house and agreed that the flooring that was installed was wet. They recommended doing a moisture test on every single board that was laid which is absolutely ridiculous... they gave us half of our money back and an extra 500 ft.² of flooring to try to make it right. My husband is a class a contractor, and unbelievably handy... and decided to tackle the project, because after building this house we’ve learned that if you want something done right you have to do it yourself! He ripped out the largest section of flooring that had the worst gaps and has replaced a section and has done individual board replacement for some of the isolated terrible boards. We are hired the best finisher in the area and he is $$$$$... but hopefully he will do a good job. We are going to do a little bit of filling with Woodwise, because we got a whole house humidifier to try to keep the humidity stable. The basement is fully finished, so hopefully won’t have moisture issues. I have attached some before and after photos. This has been no small projects, my husband has spent hours upon hours custom fitting each board it’s absolutely ridiculous. My recommendation is to get it right the first time or send the flooring back and don’t install something subpar

Before