Cannot create a new visualization in Firefox and Safari

[marius-dr]

Kibana version: 7.7.0

Browser version: Firefox 75, Safari

Original install method (e.g. download page, yum, from source, etc.): BC10

Describe the bug:
If you try to create a new TSVB, Timelion, Vega, Input Control visualization in Firefox or Safari, it just loops back to the visualizations table without opening.
Opening an existing TSVB visualizations (one of the sample ones) works just fine.

Steps to reproduce:

1. Try to create new TSVB visualization from the visualization page.

Any additional context:
No errors in browser console, network requests or in the server logs.

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[marius-dr]

Firefox:
Looks like most of the others have similar issues when creating, except it's intermittent. TSVB, Vega and Timelion are 100%, the others are less affected, but I've reproduced it with Gauge, Input Control, Data Table and Area chart as well. Seems that after one of them fails, there is stuff remaining in the URL from the supposed opened one so that might affect subsequent creations.

Incognito mode doesn't make any difference either, so it's not a cache issue.

[bhavyarm]

Please note on safari - this seems intermittent - I was able to create TSVB and timelion vizs. But the failure rate is way higher than success rates.

[bhavyarm]

add new visualization from dashboard works on safari for timelion and TSVB.

[marius-dr]

Same of Firefox: i can create a new TSVB from Create New on the Dashboards, so it seems localized to the visualization page.