With crashing MySQL I mean that the server process terminates and the whole database (including phpMyAdmin) is not reachable until it is automatically restarted half a minute later.
This is the result of php flarum info so far. I am still trying to get the mysql logs from my hoster:
web333@s272 ~/www/forum # php7.4 flarum info
Flarum core 1.2.0
PHP version: 7.4.27
MySQL version: 8.0.20
Loaded extensions: Core, date, libxml, openssl, pcre, zlib, filter, hash, pcntl, Reflection, SPL, session, standard, sodium, mysqlnd, PDO, xml, apcu, bcmath, bz2, calendar, ctype, curl, dba, dom, enchant, mbstring, FFI, fileinfo, ftp, gd, gettext, gmp, iconv, imagick, imap, intl, json, ldap, exif, mysqli, odbc, pdo_dblib, PDO_Firebird, pdo_mysql, PDO_ODBC, pdo_pgsql, pdo_sqlite, pgsql, apc, posix, pspell, readline, shmop, SimpleXML, snmp, soap, sockets, sqlite3, sysvmsg, sysvsem, sysvshm, tidy, tokenizer, xmlreader, xmlrpc, xmlwriter, xsl, zip, Phar, Zend OPcache
+----------------------+----------+--------+
| Flarum Extensions | | |
+----------------------+----------+--------+
| ID | Version | Commit |
+----------------------+----------+--------+
| flarum-flags | v1.2.0 | |
| flarum-tags | v1.2.0 | |
| flarum-suspend | v1.2.0 | |
| flarum-subscriptions | v1.2.0 | |
| flarum-sticky | v1.2.0 | |
| flarum-statistics | v1.2.0 | |
| flarum-nicknames | v1.2.0 | |
| flarum-mentions | v1.2.0 | |
| flarum-markdown | v1.2.0 | |
| flarum-lock | v1.2.0 | |
| flarum-likes | v1.2.0 | |
| flarum-lang-russian | 1.1.1-p3 | |
| flarum-lang-italian | 1.1.9 | |
| flarum-lang-german | 1.1.4 | |
| flarum-lang-french | v3.5.0 | |
| flarum-lang-english | v1.2.0 | |
| flarum-emoji | v1.2.0 | |
| flarum-bbcode | v1.2.0 | |
| flarum-approval | v1.2.0 | |
+----------------------+----------+--------+
Base URL: https://forum.pianoscope.app
Installation path: /home/www/forum
Queue driver: sync
Mail driver: smtp
Debug mode: off
web333@s272 ~/www/forum #