That's the reason you should use
certbot -d rinex.org.rw -d www.rinex.org.rw
so certbot can find the certificate and ask, if you want to install it.
Oh - I see the problem. What's your server software?
https://rinex.org.rw/
196.49.7.181
200
2.520
I
Date: Thu, 23 May 2019 09:55:13 GMT
Vary: Cookie,Accept-Encoding
Composed-By: SPIP 3.0.20 @ www.spip.net + spip(3.0.20),compagnon(1.4.1),dump(1.6.9),images(1.1.10),forum(1.8.40),jqueryui(1.8.21),mediabox(0.8.11),mots(2.4.13),msie_compat(1.2.0),organiseur(0.8.12),petitions(1.4.6),porte_plume(1.12.4),revisions(1.7.9),safehtml(1.4.1),sites(1.7.13),squelettes_par_rubrique(1.1.1),stats(0.4.28),svp(0.80.26),urls(1.4.26),vertebres(1.2.2),yaml(1.5.2),saisies(2.6.1),ckeditor(0.16.19),iterateurs(0.6.1),queue(0.6.6),breves(1.3.6),compresseur(1.8.11),medias(2.7.66),tw(0.8.30)
X-Spip-Cache: 86400
Last-Modified: Thu, 23 May 2019 09:55:13 GMT
Connection: close
Transfer-Encoding: chunked
There is no Apache/nginx header.
How did you install your current certificate?
Do that again.