Some URLs are reported as invalid but are OK

[camilleroux]

Here are some URLs that are really working in Firefox but are reported as invalid :

 https://doi.org/10.1007/s10072-020-04447-w is an invalid URL
 https://www.researchgate.net/profile/Dan_Ward9/publication/340539075_Sampling_Bias_Explaining_Wide_Variations_in_COVID-19_Case_Fatality_Rates/links/5ea67986299bf11256128426/Sampling-Bias-Explaining-Wide-Variations-in-COVID-19-Case-Fatality-Rates.pdf  is an invalid URL
 https://www.sciencedirect.com/science/article/pii/S1477893920303124 is an invalid URL
 https://doi.org/10.1038/s41586-020-2349-y is an invalid URL
 https://www.sciencedirect.com/science/article/pii/S0001879119301265?casa_token=h2tOm3iqTmYAAAAA:oNK0sZvDVXxE2O1Sr46BiC2zGLnhQ1kQt1DIhX0c-jq6yZsh7fw78cOK0t2zVkqcguscB4BdZ-c is an invalid URL
 https://kjhrm.sljol.info/articles/10.4038/kjhrm.v12i1.41/galley/76/download/ is an invalid URL
 https://doi.org/10.3201/eid2607.200885 is an invalid URL
 http://faculty.washington.edu/jdb/articles/Brown%20(2012,%20PSPB,%20motives).pdf is an invalid URL
 https://www.sciencedirect.com/science/article/pii/S0006291X20314169 is an invalid URL
 https://www.medrxiv.org/content/10.1101/2020.04.07.20045617v1 is an invalid URL
 https://obgyn.onlinelibrary.wiley.com/doi/full/10.1002/ijgo.13182 is an invalid URL
 https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death  is an invalid URL
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170399/  is an invalid URL
 https://doi.org/10.1016/S1473-3099(20)30287-5 is an invalid URL
 https://www.medrxiv.org/content/10.1101/2020.03.05.20031815v1.full.pdf is an invalid URL

[camilleroux]

Spaces before or after seems to be the reason