Duplicate skill gems in full DPS causes incorrect DPS calculations

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• I'm running the latest version of Path of Building and I've verified this by checking the changelog

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• I've checked for duplicate issues by using the search function of the issue tracker

What is the expected behaviour/value?

DPS Calculations should accurately show more/less changes to the skill.

What is the actual behaviour/value?

DPS appears to inconsistently either show the final calc values, or an impossibly large more damage multiplier.

How to reproduce the issue

If you wish to observe from nothing. The properties here appear to be slightly different. Ballista totem needs to be present as a link for a variant of the bug to appear.

1. Add a bow to an empty build.
2. Go to skills tab.
3. Add 2 instances of Toxic Rain, one without links and the other with ballista totem. Enable "Include in FUll DPS" for both
4. Start to add support gems to the first Toxic Rain.

In the PoB provided below, ballista totem does not appear to affect the outcome of the bug.

1. Go to skills tab
2. Select Toxic Rain (6)
3. Attempt to change an enabled support to a new gem.

Steps to temporarily fix the bug from the PoB provided.

1. Go to skills tab.
2. Select TR Totem (5).
3. Disable "Include in Full DPS."
4. Switch to Toxic Rain (6).
5. Attempt to change an enabled support gem to a new gem.

Character build code

https://pobb.in/hPql3eZ74-8F

Screenshots

Import the provided build code from pobb.in, open the Skills tab, and reproduce the issue by enabling two Toxic Rain instances in Full DPS and changing a support gem. Compare the displayed more/less damage changes with the expected behavior shown in the screenshots; done means duplicate skill gems no longer produce inconsistent or impossibly large DPS multipliers.