Problem to update firmware on GrandStream GXP11XX, GXP14XX, GXP21XX

GXP1100/GXP1105/GXP1160/GXP1165
GXP1400/GXP1405/GXP1450
GXP2100/GXP2110/GXP2120/GXP2124

Firmware release bundles:

GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.4.23
GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.5.15
GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.5.23
GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.5.24
GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.5.26
GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.6.11
GrandStream GXP11XX, GXP14XX, GXP21XX 1.0.8.6

From version 1.0.1 it was possible to successfully upgrade to version 1.0.4. then to version 1.0.5.26 then to version 1.0.6.11 and 1.0.8.6

Firmware Server path for GXP2120

semos-icare.eu/grandstream/1.0.4.23/
semos-icare.eu/grandstream/1.0.5.15/
semos-icare.eu/grandstream/1.0.5.23/
semos-icare.eu/grandstream/1.0.5.24/
semos-icare.eu/grandstream/1.0.5.26/
semos-icare.eu/grandstream/1.0.6.11/
semos-icare.eu/grandstream/1.0.8.6/