My theory....
If it plugged up with sediment, the flow would just get really slow. A new one shouldn't plug up that quick either. So this can't be it.
Just because you read 40 - 45 psi when you look at it doesn't mean there wasn't higher pressure than that if there was high inlet pressure (before regulator) for long enough. Those inline regulators just have a restrictor orifice in them. I think the only plausible theory would be damage from high pressure. Many plumbing fittings and components have a working pressure rating or burst pressure rating. Is there a rating on the Camco filter or in the package? There is nothing on pressure on the Camco site.
Do you trust your gauge?
If the 2nd filter failed that quickly, I suspect sustained high pressure long enough to damage the filter. The inlet and outlet pressure would tend to equalize (zero pressure differential) if just sitting there at zero flow long enough. It only regulates by way of a small diameter hole and not by a diaphram. The only thing I could quickly find on the internet to show this is this:
orifice restrictor regulation This shows that the inline type of RV regulator may be a poor choice for good protection.
Are you near the main point of supply for the CG where pressure would be highest? If you were at the farthest site from their point of supply, the pressure would be somewhat lower due to pressure loss in the piping system. They may have the pressure set on the high side so that when there are a lot of users on the systems in the peak system, the sites farthest away have adequate pressure. Is it on a municipal public water system or a private on-site well system? If you are tasting chlorine, I am guessing a public system, which would typically have a more stable pressure level, but that doesn't mean the pressure could not be high in the RV park. Is the park near any other large water users (casino, ex.)?
I would ditch the inline regulator and inline filter. The Camco filter is only good for about 1 gpm and if it is the KDF/carbon one, it only filters down to 100 micron.
Get a 10" whole house filter (as mentioned above) and a sediment filter with a smaller micron rating like 5 micron. You could get a combo filter with a carbon filter in it. Get a better diaphragm type regulator like the Watts 560 series or better, the 263A series. You could install one inside or outside, but if inside, get a high pressure Valterra hose.
Until you make any changes just don't use an inline filter and use bottled water for drinking if you want.
