The dig result you asked for is at post 18 - or by waiting period I guess you mean while certbot is doing the 2 min dns propagation i will run it and then edit this
EDIT
[root@main ~]# dig @localhost _acme-challenge.xxxxxxxx.com TXT
; <<>> DiG 9.9.4-RedHat-9.9.4-61.el7 <<>> @localhost _acme-challenge.xxxxxxxx.com TXT
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18692
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 3
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;_acme-challenge.xxxxxxxx.com. IN TXT
;; ANSWER SECTION:
_acme-challenge.xxxxxxxx.com. 120 IN TXT “qH5GT_row8vPRP-oVxnoBkRWB5tt5fBoy0QyyBN4hWU”
_acme-challenge.xxxxxxxx.com. 120 IN TXT “5l5vWFIUQlhgMrqZnkDnc5h2hIYsbNHZzf3EV8Ucm2M”
;; AUTHORITY SECTION:
xxxxxxxx.com. 172798 IN NS ns1.yyyyyyy.com.
xxxxxxxx.com. 172798 IN NS ns2.yyyyyyy.com.
;; ADDITIONAL SECTION:
ns1.yyyyyyy.com. 172798 IN A xxx.xxx.xxx.xxx
ns2.yyyyyyy.com. 172798 IN A xxx.xxx.xxx.xxx
;; Query time: 4129 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Aug 10 19:36:57 CDT 2018
;; MSG SIZE rcvd: 252
Still the same - no TXT record found - and then the TXT entries above are gone after cleanup and the run completed
Domain: xxxxxxxx.com
Type: unauthorized
Detail: No TXT record found at _acme-challenge.xxxxxxxx.com
Further - while it writes a jnl file, it does not write to the zone file - and if the dig is refreshed while waiting the TXT field changes like a moving target.
I am sure the key was working as previously it modified the zone file