@Brumiga: thanks for the info, bizarre not precised in release note of MorphOS 3.19, just "Devs/Monitors/Radeon : Modified debug output"

I have compared version numbers and date:

R200.library is more recent in last TinyGL archive (53.6 instead 53.4 on MorphOS 3.19)
R300.library is more recent in last TinyGL archive (53.12 instead 53.10 on MorphOS 3.19)
R600.library is not present in MorphOS 3.19
TinyGL and Freeglut librairies and Radeon monitor file have same version and same date