I had the the same issue with a Bontrager wheel from back in 2006 time period. Pain. Had the shop tension the wheel many times. As said above the rim eventually will crack. Trek replaced it under warranty. Second wheel the same problem. I’ve built a few wheels so figured some spike prep was needed. Did not want to completely rebuilt so used some green wicking Loctite. Helped so I’d only get loose spokes every few months. After 11 years the wheel rim cracked. Oh this was an aluminum rear wheel. So upgraded to Aeoles Pro 5 wheels. May be the deep rim but never touch them. After the Madone frame broke these carbon wheels are on a rail trail, lite touring, bad weather bike.

Permatex makes a wicking thread locker version. Heck nail polish would work and add color. I’d thread lock the offending spokes and keep and eye on the rim. Then budget for new wheel.