And this is where I likely n00bed it up pretty hard. Generally I operate strictly off packages - and really haven’t done thorough research / reading on all the different elements at play here. Although I wasn’t using nginx - I still was getting blasted with that security issue and figured I’d try and upgrade the php version anyway. That’s when it all went down hill. Unfortunately/Fortunately I tend to learn better when breaking things, and then figuring out what broke and how to fix it. Unfortunately/Fortunately I wasn’t able to resolve it myself (or in a timely enough manner) and resort to begging 
root@nextcloud:/usr/local # php -i | grep php.ini
Configuration File (php.ini) Path => /usr/local/lib
Clearly no php.ini loaded when stare and comparing to your example. Decided to wildcard search the location for any php oriented results.
root@nextcloud:/usr/local/lib # ls -l *php*
-rwxr-xr-x 1 root wheel 5401837 Jul 13 20:12 libphp7.so
php:
total 107
drwxr-xr-x 3 root wheel 7 Oct 24 21:51 .channels
-rw-r--r-- 1 root wheel 2470 Oct 24 21:51 .depdb
-rw-r--r-- 1 root wheel 0 Oct 24 21:51 .depdblock
-rw-r--r-- 1 root wheel 6961 Oct 24 21:51 .filemap
-rw-r--r-- 1 root wheel 0 Oct 24 21:51 .lock
drwxr-xr-x 5 root wheel 10 Oct 24 21:51 .registry
drwxr-xr-x 2 root wheel 32 Jul 20 00:21 20180731
drwxr-xr-x 2 root wheel 3 Oct 24 21:51 Archive
drwxr-xr-x 2 root wheel 15 Oct 24 21:51 build
drwxr-xr-x 2 root wheel 3 Oct 24 21:51 Console
drwxr-xr-x 3 root wheel 3 Oct 24 21:51 data
drwxr-xr-x 6 root wheel 6 Oct 24 21:51 doc
drwxr-xr-x 3 root wheel 3 Oct 24 21:51 extensions
drwxr-xr-x 2 root wheel 3 Oct 24 21:51 OS
drwxr-xr-x 11 root wheel 31 Oct 24 21:51 PEAR
-rw-r--r-- 1 root wheel 35467 Oct 24 21:51 PEAR.php
-rw-r--r-- 1 root wheel 15028 Oct 24 21:51 pearcmd.php
-rw-r--r-- 1 root wheel 1025 Oct 24 21:51 peclcmd.php
drwxr-xr-x 3 root wheel 4 Oct 24 21:51 Structures
-rw-r--r-- 1 root wheel 20562 Oct 24 21:51 System.php
drwxr-xr-x 5 root wheel 5 Oct 24 21:51 test
drwxr-xr-x 2 root wheel 3 Oct 24 21:51 XML
While I was blindly shooting in the dark, I remember that dated folder being specified somewhere so I decided to check it out. There seems to be the modules, including the pdo_mysql.so
root@nextcloud:/usr/local/lib/php/20180731 # ls -l
total 3231
-rw-r--r-- 1 root wheel 78656 Jul 13 20:18 apcu.so
-rw-r--r-- 1 root wheel 21912 Jul 13 20:17 bz2.so
-rw-r--r-- 1 root wheel 12040 Jul 13 20:14 ctype.so
-rw-r--r-- 1 root wheel 93936 Jul 13 20:17 curl.so
-rw-r--r-- 1 root wheel 190792 Jul 13 20:13 dom.so
-rw-r--r-- 1 root wheel 86768 Jul 13 20:17 exif.so
-rw-r--r-- 1 root wheel 5436536 Jul 13 20:16 fileinfo.so
-rw-r--r-- 1 root wheel 45952 Jul 13 20:15 filter.so
-rw-r--r-- 1 root wheel 108032 Jul 13 20:16 gd.so
-rw-r--r-- 1 root wheel 259384 Jul 13 20:14 hash.so
-rw-r--r-- 1 root wheel 41960 Jul 13 20:15 iconv.so
-rw-r--r-- 1 root wheel 460712 Jul 13 20:17 intl.so
-rw-r--r-- 1 root wheel 44920 Jul 13 20:14 json.so
-rw-r--r-- 1 root wheel 84056 Jul 13 20:15 ldap.so
-rw-r--r-- 1 root wheel 1078704 Jul 13 20:15 mbstring.so
-rw-r--r-- 1 root wheel 535808 Jul 13 20:18 opcache.so
-rw-r--r-- 1 root wheel 185080 Jul 13 20:15 openssl.so
-rw-r--r-- 1 root wheel 26024 Jul 13 20:17 pdo_mysql.so
-rw-r--r-- 1 root wheel 107048 Jul 13 20:15 pdo.so
-rw-r--r-- 1 root wheel 34784 Jul 13 20:16 posix.so
-rw-r--r-- 1 root wheel 514784 Jul 13 20:31 redis.so
-rw-r--r-- 1 root wheel 95392 Jul 13 20:14 session.so
-rw-r--r-- 1 root wheel 59136 Jul 13 20:18 simplexml.so
-rw-r--r-- 1 root wheel 30296 Jul 13 20:17 wddx.so
-rw-r--r-- 1 root wheel 52760 Jul 13 20:13 xml.so
-rw-r--r-- 1 root wheel 34336 Jul 13 20:17 xmlreader.so
-rw-r--r-- 1 root wheel 46328 Jul 13 20:17 xmlwriter.so
-rw-r--r-- 1 root wheel 33672 Jul 17 22:05 xsl.so
-rw-r--r-- 1 root wheel 62312 Jul 13 20:16 zip.so
-rw-r--r-- 1 root wheel 48256 Jul 13 20:13 zlib.so
I recall seeing that folder being defined at this location / php.conf:
root@nextcloud:/usr/local/etc # ls -l php.conf
-rw-r--r-- 1 root wheel 99 Oct 24 22:15 php.conf
GNU nano 4.2 php.conf
PHP_VER=73
PHP_VERSION=7.3.11
PHP_SAPI=cli cgi fpm embed
PHP_EXT_INC=pcre spl
PHP_EXT_DIR=20180731
Which, I feel all of that is all over the place - once again likely due to my lack of experience. So I do apologize for that but I do appreciate your guidance along the way. If I don’t hear anything back in the next couple days or so I can definitely WANT to and can look further into how to resolve this - just tonight won’t allow me the time to do so.
Thanks once again.