My understanding of that gen Honda (had a 2003 a while) is that the rubber seals on the solenoids harden prematurely vs. other makes; poor material choice/quality control issue at the root. I had good success softening them with additives - may or not be a long time solution. But just some background on your likely problem. So physically, yes, they can leak a bit, make lower pressure than desired, but still function.
The external solenoid mounts on those transmission are genius and I wish that was more common. The cost to replace the solenoids on the 2003 Civic was really small compared to most transmissions.