Deficit

I have a Deficit XSS 712 score after doing a 7 hour ride that was shared with Xert through Strava (outside gravel ride). Why did this add to my deficit instead of subtracting?

A reasonable question. Best raise a support call.

How often are you putting in 7 hour rides?
What is your Improvement Rate set to under Program?
Post your XPMC chart set to 3 months with only TL and XSS enabled.

I was scheduled to do a 3hr Friday (zone 2) and a 3hr Saturday (zone 2) but I knew I couldn’t ride today (Saturday) so I put in a long ride. RPE wasn’t high. I’m set at extreme 1.

XATA considers your history against your Program settings when determining deficit/surplus which can jump day to day. The value also doesn’t carry over from one day to the next.
Watch what happens to the number when you lower your IR (Improvement Rate) from Extreme to Moderate.
Before I get into that further, we need to address your fitness signature values.

ScottLaymanSig

Compare your current signature to this chart.
What trainer and bike power meter are you riding that captured your historical power data?
Is your historical data strictly from cycling activities?
What is the typical Peak Power shown and Max Power recorded in your activity history?
You’ll need to add Max Power to the table. This should be done on a PC/laptop/tablet. A phone view won’t display everything you need to look at although you could try rotating phone to landscape mode and enabling desktop view on your mobile browser.
Also, is the tall activity from November correct? How long a ride was that?

All of my rides were imported from Garmin. My outdoor rides are with a Quarq power meter on MTB. The spike was from a 12 mile MTB ride I did that was a time trial with some younger riders. Most of the rides I was doing from late November were on a Stages indoor trainer because I had shoulder surgery. The last long ride that didn’t register any XSS was on a gravel bike without a power meter and was my first outdoor ride since November.

First try removing any obvious power spikes from signature calculations by flagging them.
Flagging an activity retains the strain score but excludes it from signature calcs.
Easiest way to do this is Activities, Table, add Max Power as a column, sort by that column, tick any entries with obvious power spikes then select Flag button in upper right.
See how that affects your signature.

There is an entry at the beginning of your XPMC chart that shows 1800 XSS. What was that from?

The major problem is it didn’t register any XSS for my ride. Why is that? Can i manually put something in like a RPE? I rely primarily on Garmin and Training Peaks for my metrics because I’m using a coach programmed training plan. I’m just experimenting with Xert because I was thinking about using it exclusively next off season.

It seems your signature is too far off to properly analyze your activities with power data.
Best to file a support ticket by contacting support@xertonline.com so they can review your historical data and make manual adjustments as necessary.

The activity entry I am referring to is on the far left of the chart view you posted.
It appears to show 1800 XSS would be a massive effort such as a 24-hour event ridden at a difficult 75 XSS/hour.