I do have an Economics degree and work in Global Markets for one of the largest financial service providers on the planet - definitely the largest Financial Data provider on the planet.
The USDX is not really an indicator of inflation. It is more for arbitrage and weighs the US dollar against 6 other currencies, each weighted differently in the calculation. Missing from that calculation are the currencies of the #2 and #6 largest economies in the world - China and India. In many ways, CPI misses the mark on true inflation - it does not account for price increases in durable consumer goods, insurance premiums, college tuition, used-car prices etc. It also is an aggregation of the whole country, not a regional number - and the US has many economic stratifications correlating to regions and sub-regions.
Quantitative Easing from 2009 through 2014 was a hyper injection of liquidity into the monetary system should have caused an immediate spike in inflation, but banks held onto the money as reserves to bolster their balance sheets for years - that money slowly trickled into the system and is a large part of why we are seeing inflation now. Of course, there are other significant factors. The pandemic and the responding legislation compounded the effects of QE and the absurdly long run of low interest rates. While we all understand the intention and there were absolutely people that needed the expansion of unemployment benefits, it was done in a way that is analogous to using a chainsaw when a scalpel is required. Compound that with the $1.9 trillion that was dumped into the system earlier in 2021 and we are in inflation soup (never mind the supply chain issues that are persisting far longer than anyone could have imagined).