List of WMS / WMTS services that have some issues

[RicardCots]

Describe the bug
List of WMS / WMTS services presented have some issues

1. The administrator is unable to retrieve the WMS service layers in the service edit form.
https://ovc.catastro.meh.es/cartografia/INSPIRE/spadgcwms.aspx

2. The administrator does not retrieve the layer tree structure from the 'load from service' functionality of the layer tree edit form

3. The SITMUN client shows some error with these services:
https://ovc.catastro.meh.es/cartografia/INSPIRE/spadgcwms.aspx
https://idena.navarra.es/ogc/wmts
https://ideib.caib.es/geoserveis/rest/services/imatges/GOIB_Ortofoto_2018_IB/MapServer/WMTS
https://ideib.caib.es/geoserveis/rest/services/imatges/GOIB_Ortofoto_2015_IB/MapServer/WMTS
(AND ALL WMTS FROM GOIB)

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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Desktop (please complete the following information):

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Smartphone (please complete the following information):

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Additional context
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[fjlopez]

@RicardCots please, split this issue in 3 different issues if needed.

1. In the specific case https://ovc.catastro.meh.es/cartografia/INSPIRE/spadgcwms.aspx the cause is that there is a socket timeout problem when connecting from the backend to the Catastro server.
2. Is is the consequence of the above or is it something different?
3. Which kind of errors?

[fjlopez]

Error Undefined when obtainng data:
https://wms.mapama.gob.es/sig/Biodiversidad/INESErosionPotencial/wms.aspx