ubuntu 18.04 reconcile fails

[br-olf]

I'm using acmetool to get a certificate for my server at home (dynamic IP + dynamic DNS updates).
I've used the stateless configuration with nginx.

This worked fine for some time but now the reconcile fails with the following error:

20190319161115 [DEBUG] fdb: enforce permissions: tmp/symlink.678345275 0/0 0/0
20190319161115 [DEBUG] acme.storageops: Certificate(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) satisfies Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0)
20190319161115 [DEBUG] acme.storageops: Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0): best certificate satisfying is Certificate(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx), err=<nil>
20190319161115 [DEBUG] acme.storageops: Certificate(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) needsRenewing=true notAfter=2019-04-07 22:35:44 +0000 UTC
20190319161115 [DEBUG] acme.storageops: Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0): requesting certificate
20190319161115 [DEBUG] acme.api: request: https://acme-v01.api.letsencrypt.org/directory
20190319161126 [DEBUG] acme.api: response: &{200 OK 200 HTTP/1.1 1 1 map[Strict-Transport-Security:[max-age=604800] Expires:[Tue, 19 Mar 2019 16:11:26 GMT] Cache-Control:[max-age=0, no-cache, no-store] Pragma:[no-cache] Date:[Tue, 19 Mar 2019 16:11:26 GMT] Server:[nginx] Content-Length:[658] X-Frame-Options:[DENY] Content-Type:[application/json] Replay-Nonce:[b6Ad2K9HsoSwenLrrFhg6WFCZ9uQnAiqRrG_6eQn-MU] Connection:[keep-alive]] 0xc4203c6040 658 [] false false map[] 0xc4201a4500 0xc4200dcbb0} <nil>
20190319161126 [DEBUG] acme.api: request: https://acme-v01.api.letsencrypt.org/acme/new-reg
20190319161126 [DEBUG] acme.api: response: &{409 Conflict 409 HTTP/1.1 1 1 map[Content-Type:[application/problem+json] Content-Length:[107] Boulder-Requester:[49105466] Replay-Nonce:[aI-wzbQ1wloR_lgRX3rswjIgK5GB4VswcSbHyPR7pCw] Expires:[Tue, 19 Mar 2019 16:11:26 GMT] Pragma:[no-cache] Date:[Tue, 19 Mar 2019 16:11:26 GMT] Server:[nginx] Location:[https://acme-v01.api.letsencrypt.org/acme/reg/49105466] Cache-Control:[max-age=0, no-cache, no-store]] 0xc4203c6180 107 [] true false map[] 0xc4201a4300 0xc4200dcbb0} <nil>
20190319161126 [DEBUG] acme.api: request: https://acme-v01.api.letsencrypt.org/acme/reg/49105466
20190319161156 [DEBUG] acme.api: response: <nil> Post https://acme-v01.api.letsencrypt.org/acme/reg/49105466: dial tcp 104.74.120.43:443: i/o timeout
20190319161156 [ERROR] acme.storageops: Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0): failed to request certificate: Post https://acme-v01.api.letsencrypt.org/acme/reg/49105466: dial tcp 104.74.120.43:443: i/o timeout
20190319161156 [DEBUG] acme.storageops: done processing targets, reconciliation complete, 1 errors occurred
20190319161156 [ERROR] acme.storageops: error while processing targets: the following errors occurred:
error satisfying Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0): Post https://acme-v01.api.letsencrypt.org/acme/reg/49105466: dial tcp 104.74.120.43:443: i/o timeout
20190319161156 [ERROR] acme.storageops: failed to reconcile: the following errors occurred:
error satisfying Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0): Post https://acme-v01.api.letsencrypt.org/acme/reg/49105466: dial tcp 104.74.120.43:443: i/o timeout
20190319161156 [DEBUG] fdb: enforce permissions: tmp/symlink.089992286 0/0 0/0
20190319161156 [DEBUG] acme.storageops: disjoint hostname mapping: mydomain.net -> Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0)
20190319161156 [DEBUG] acme.storageops: Certificate(xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) satisfies Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0)
20190319161156 [CRITICAL] acmetool: fatal: reconcile: the following errors occurred:
error satisfying Target(mydomain.net;https://acme-v01.api.letsencrypt.org/directory;0): Post https://acme-v01.api.letsencrypt.org/acme/reg/49105466: dial tcp 104.74.120.43:443: i/o timeout

I have a sometimes very slow internet connection.
If the problem are related to the timeouts is there a possibility to increase them?