Can't logon anymore after 6.5.2 upgrade

Hello,
I have upgraded a test projeqtor install from 6.5.2 to 6.5.3 and can't login anymore? so i upgraded to 6.5.4 when it was available and then to 6.5.5 but still i am getting "Mise à jour en cours. Seul un administrateur peut se connecter"
In projeqtor log, i get the following messages with debug set to 4:
2018-02-12 00:36:44.829

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DEBUG

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loginCheck : current db version = 'V6.5.2'
2018-02-12 00:36:44.832

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DEBUG

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User->authenticate('admin', 'c2xxxyyyzzz72')
2018-02-12 00:36:44.834

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DEBUG

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User->authenticate : sha256 encryption
2018-02-12 00:36:44.834

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DEBUG

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User->authenticate : Successfull login
2018-02-12 00:38:23.127 ..... SCRIPT .... 197.17.63.134 =====/view/main.php
2018-02-12 00:38:23.140 ..... SCRIPT .... 197.17.63.134 Page=main.php
2018-02-12 00:38:23.170 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=User #1)
2018-02-12 00:38:23.172 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=User #1)
2018-02-12 00:38:23.179 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=History #)
2018-02-12 00:38:23.183 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=History #)
2018-02-12 00:38:23.227 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=)
2018-02-12 00:38:23.245 ===== TRACE ===== NEW CONNECTED USER 'admin' (using remember me feature)
2018-02-12 00:38:23.248 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=Audit #)
2018-02-12 00:38:23.248 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=Audit #)
2018-02-12 00:38:23.251 ..... SCRIPT .... 197.17.63.134 ->/view/main.php
2018-02-12 00:38:23.252 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=Audit #84)
2018-02-12 00:38:23.252 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=Audit #84)
2018-02-12 00:38:23.265 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=AuditSummary #)
2018-02-12 00:38:23.266 ..... SCRIPT .... 197.17.63.134 getProfile(objectOrIdProject=AuditSummary #)
2018-02-12 00:38:23.276 ===== TRACE ===== DISCONNECTED USER 'admin'
2018-02-12 00:38:23.278 ..... SCRIPT .... 197.17.63.134 ->/view/login.php
2018-02-12 00:38:37.719 ..... SCRIPT .... 197.17.63.134 =====/tool/saveDataToSession.php
2018-02-12 00:38:37.751 ..... SCRIPT .... 197.17.63.134 Page=saveDataToSession.php
2018-02-12 00:38:37.847 ..... SCRIPT .... 197.17.63.134 =====/tool/saveDataToSession.php
2018-02-12 00:38:37.876 ..... SCRIPT .... 197.17.63.134 Page=saveDataToSession.php
2018-02-12 00:38:37.947 ..... SCRIPT .... 197.17.63.134 =====/tool/saveDataToSession.php
2018-02-12 00:38:37.954 ..... SCRIPT .... 197.17.63.134 =====/tool/saveDataToSession.php
2018-02-12 00:38:37.965 ..... SCRIPT .... 197.17.63.134 =====/tool/saveDataToSession.php
2018-02-12 00:38:37.979 ..... SCRIPT .... 197.17.63.134 =====/tool/saveDataToSession.php
2018-02-12 00:38:38.046 ..... SCRIPT .... 197.17.63.134 Page=saveDataToSession.php
2018-02-12 00:38:38.082 ..... SCRIPT .... 197.17.63.134 Page=saveDataToSession.php
2018-02-12 00:38:38.083 ..... SCRIPT .... 197.17.63.134 Page=saveDataToSession.php
2018-02-12 00:38:38.090 ..... SCRIPT .... 197.17.63.134 Page=saveDataToSession.php
I have to mention that i had trouble before when i upgraded to 6.5.2 and was able to login again by restoring database from another projeqtor installation on which upgrade to 6.5.2 went smooth.
TIA.

babynus wrote: Tryu and clean browser cache and delete cookies.

Did as you said, but the result is the same.
In fact, It's sometime I am trying, from home, work, smartphone with the same result. So, I don't think its a browser cache issue.
I forgot to mention that this ProjeQtor installation is running on CentOS 7.4, php7.2.2( from rémi repo) and postgresql 10.2