Onlyoffice wss error with apache2 proxy and docker

Hi,
OnlyOffice open but I always have a wss error an unable to save the file :
WebSocket connection to ‘wss://seafileurl/onlyofficeds/5.4.1-39//doc/59604a30deb0a884396f/c/364/eynhgold/websocket’ failed: Unexpected response code: 400

My configuration :
Docker container Seafile : 6.3.4
Docker container Onlyoffice : 5.4.1.39 (name: oods)
f289bab5f7f5 onlyoffice/documentserver “/bin/sh -c /app/onl…” 44 minutes ago Up 44 minutes 443/tcp, 0.0.0.0:88->80/tcp oods

client <-https-> host apache2 <-http-> docker container seafile
client <-https-> host apache2 <-http-> docker container onlyoffice

container seafile > seahub_settings.py :

# Enable Only Office
ENABLE_ONLYOFFICE = True
VERIFY_ONLYOFFICE_CERTIFICATE = False
ONLYOFFICE_APIJS_URL = 'https://<seafileurl>/onlyofficeds/web-apps/apps/api/documents/api.js'
ONLYOFFICE_FILE_EXTENSION = ('doc', 'docx', 'ppt', 'pptx', 'xls', 'xlsx', 'odt', 'fodt', 'odp', 'fodp', 'ods', 'fods')
ONLYOFFICE_EDIT_FILE_EXTENSION = ('docx', 'pptx', 'xlsx')

host (Ubuntu 19.04) > Apache/2.4.38 > sites-enabled > vhost :

    <IfModule unixd_module>
      User daemon
      Group daemon
    </IfModule>
    <IfModule mod_ssl.c>
    <VirtualHost *:443>

    ...

    #
    # onlyofficeds
    #
    # a2enmod proxy_wstunnel

    Define VPATH /onlyofficeds
    # 127.0.1.1 is host ip, port 88 is open in ufw
    Define DS_ADDRESS 127.0.1.1:88

    <Location ${VPATH}>
    LimitRequestBody 200000000
    Require all granted
    SetEnvIf Host "^(.*)$" THE_HOST=$1
    RequestHeader setifempty X-Forwarded-Proto https
    RequestHeader setifempty X-Forwarded-Host %{THE_HOST}e
    RequestHeader edit X-Forwarded-Host (.*) $1${VPATH}
    ProxyAddHeaders Off
    ProxyPass "http://${DS_ADDRESS}/"
    ProxyPassReverse "http://${DS_ADDRESS}/"
    </Location>

    </VirtualHost>
    </IfModule>

I spend many hours to try many configurations to make it working but without sucess. I need help. Thanks.