After updating Nextcloud, the collabora/code Docker image, and the Nextcloud Collabora app, I no longer have this problem.
Operating system: Linux 5.7.2-arch1-1 #1 SMP PREEMPT Wed, 10 Jun 2020 20:36:24 +0000 x86_64
Webserver: nginx/1.19.0 (fpm-fcgi)
Database: mysql 10.4.13
PHP version: 7.4.7
Modules loaded: Core, date, libxml, openssl, pcre, zlib, ctype, dom, fileinfo, filter, hash, json, mbstring, pcntl, SPL, PDO, apcu, posix, readline, Reflection, session, SimpleXML, standard, tokenizer, xml, xmlreader, xmlwriter, mysqlnd, cgi-fcgi, bcmath, bz2, curl, exif, ftp, gd, gettext, gmp, iconv, imap, intl, mysqli, pdo_mysql, pdo_sqlite, pspell, snmp, sockets, sqlite3, tidy, xmlrpc, xsl, zip, apc, Phar, geoip, igbinary, imagick, pam, redis, smbclient, libsmbclient, Zend OPcache
Nextcloud version: 19.0.0 - 19.0.0.12
Good luck!
buzz