GetFeatureInfo works over HTTP but not HTTPS

I have GeoServer up and running with ProxyPass allowing access over HTTPS and I have the proxy base URL set to https://maps.tellus-toolkit.com/geoserver/ Everything is working as expected apart from a GetFeatureInfo request for a WMS layer not working via HTTPS but it is working on HTTP.

I can preview the map here:

https://maps.tellus-toolkit.com/geoserver/nhs/wms?service=WMS&version=1.1.0&request=GetMap&layers=nhs%3ASG_NHS_HealthBoards_2018&bbox=5512.998599999584%2C530248.9970999993%2C470332.0037000001%2C1220301.5015999998&width=517&height=768&srs=EPSG%3A27700&styles=&format=application/openlayers

But, a request over HTTPS throws a 403 error

https://maps.tellus-toolkit.com/geoserver/nhs/wms?service=WMS&REQUEST=GetFeatureInfo&SERVICE=WMS&SRS=EPSG%3A4326&STYLES=&TRANSPARENT=true&VERSION=1.1.1&FORMAT=image%2Fpng&BBOX=-12.63427734375%2C54.93345430690937%2C4.63623046875%2C58.955674359706016&HEIGHT=672&WIDTH=1572&LAYERS=nhs%3ASG_NHS_HealthBoards_2018&QUERY_LAYERS=nhs%3ASG_NHS_HealthBoards_2018&INFO_FORMAT=text%2Fhtml&X=833&Y=404

This works though:

http://maps.tellus-toolkit.com:8080/geoserver/nhs/wms?service=WMS&REQUEST=GetFeatureInfo&SERVICE=WMS&SRS=EPSG%3A4326&STYLES=&TRANSPARENT=true&VERSION=1.1.1&FORMAT=image%2Fpng&BBOX=-12.63427734375%2C54.93345430690937%2C4.63623046875%2C58.955674359706016&HEIGHT=672&WIDTH=1572&LAYERS=nhs%3ASG_NHS_HealthBoards_2018&QUERY_LAYERS=nhs%3ASG_NHS_HealthBoards_2018&INFO_FORMAT=text%2Fhtml&X=833&Y=404

Is the problem with Tomcat/Apache reverse proxy setting or is there something in the GeoServer settings I am missing?

Here’s the output from Chrome

VM27:1 GET https://maps.tellus-toolkit.com/geoserver/nhs/wms?service=WMS&REQUEST=GetFe…_LAYERS=nhs%3ASG_NHS_HealthBoards_2018&INFO_FORMAT=text%2Fhtml&X=877&Y=242 403
(anonymous) @   VM27:1
send    @   jquery-1.10.1.min.js:6
ajax    @   jquery-1.10.1.min.js:6
getFeatureInfo  @   L.TileLayer.BetterWMS.js:21
fireEvent   @   leaflet.js:6
_fireMouseEvent @   leaflet.js:6
_onMouseClick   @   leaflet.js:6
s   @   leaflet.js:8