It's normal - nothing wrong with your setup. Chorus and flanger can add a few DB, reverb and (non extreme) delay a bit less. I just stacked chorus, delay and reverb with all parameters at 50%, and get maybe 4-5 dB increase. If I go crazy with feedback, send dry/wet it'll double that again.
This is the nature of many fx types. Chorus is a feed forward fx with multiple voices, flanger is a feedback fx, delay is a feedback fx, reverb is a feed forward fx, and so on. These are "sound on sound" fx, and so the levels can increase with unpredictable amounts. I run into the same things using fx in other scenarios. Some fx, in particular feedback ones, can be "dangerous" level wise at extreme settings.
I wouldn't worry about it, and just use the Preset Volume, which has a range of -12 to +6 dB, to take the level down when the fx are set up.