First install, on o2switch provider

Nextcloud version (eg, 20.0.5): the one you give with the use of setup-nextcloud.php
Operating system and version (eg, Ubuntu 20.04): Linux 3.10.0-962.3.2.lve1.5.24.8.el6h.x86_64 x86_64
Apache or nginx version (eg, Apache 2.4.25): replace me
PHP version (eg, 7.4): 7.3.26

{“ocs”:{“meta”:{“status”:“ok”,“statuscode”:200,“message”:“OK”},“data”:{“nextcloud”:{“system”:{“version”:“20.0.7.1”,“theme”:“none”,“enable_avatars”:“yes”,“enable_previews”:“yes”,“memcache.local”:“none”,“memcache.distributed”:“none”,“filelocking.enabled”:“yes”,“memcache.locking”:“none”,“debug”:“no”,“freespace”:247676284928,“cpuload”:[7.96999999999999975131004248396493494510650634765625,8.32000000000000028421709430404007434844970703125,8.4199999999999999289457264239899814128875732421875],“mem_total”:98960416,“mem_free”:66659828,“swap_total”:6654972,“swap_free”:6654972,“apps”:{“num_installed”:48,“num_updates_available”:0,“app_updates”:[]}},“storage”:{“num_users”:1,“num_files”:184,“num_storages”:2,“num_storages_local”:1,“num_storages_home”:1,“num_storages_other”:0},“shares”:{“num_shares”:0,“num_shares_user”:0,“num_shares_groups”:0,“num_shares_link”:0,“num_shares_mail”:0,“num_shares_room”:0,“num_shares_link_no_password”:0,“num_fed_shares_sent”:0,“num_fed_shares_received”:0}},“server”:{“webserver”:“Apache”,“php”:{“version”:“7.3.26”,“memory_limit”:536870912,“max_execution_time”:3600,“upload_max_filesize”:536870912,“opcache”:[],“apcu”:[]},“database”:{“type”:“sqlite3”,“version”:“3.26.0”,“size”:1257472}},“activeUsers”:{“last5minutes”:1,“last1hour”:1,“last24hours”:1}}}}

The issue you are facing:
Each click on a page, even the first access to a page, is very slow!
Browser is turning during 33 seconds. Then the page displays. Whatever the action, files, settings…

Same with the mobile app, some 30 seconds required before the display downloaded.