Pretty much every boat I have owned or run for a while had condensate drainage issues. Most of the the time it is because the hoses don’t have enough slope for dirt to flow out.

Another cause can be that sponge like material Cruisair has been using in the pans. After years and years the sponge becomes clogged with dirt and stuff growing resulting in the condensate overflowing on one side while the other side is flowing fine.

When i installed the new chiller air handlers on my boat I oversize the drain hose and make sure they were running as close to vertical as possible. Also Flagship has the bottom of the pans angled so water never stays in the there. Big difference.