In Argentina there's a particularly strong stagflation happening now. While a big part can be explained by "money printing"* I think there is another very important factor: inflationary inertia due to a "vicious cycle". This cycle not only includes the well known "price salary spiral" but has some more factors linked to the expectations of a continuously devaluating currency. It is composed by the following phases:
0) (see below)
1) Goods rise in price in the retail sector, because there was an increase in the wholesale price and additionally the retail merchants want to preserve their margins.
2) The consumers don't lower their consumption as they already expect price increases, instead they strive for higher salaries creating a price-salary spiral, which impacts production costs, but these cost increases alone only would explain about 30-50% of the real inflation rate.
3) When the consumers get their salary, they invest a part of it in foreign currencies (primarily the US dollar) because local currency options (like fixed bank deposits) have a meager ROI and they believe the dollar will beform better. Also, companies which import goods try to pay them as early as possible.
4) The value of the local currency decreases (compared to the dollar) due to the low demand (and high demand for foreign currencies) explained by the two mechanisms in step 3.
5) Currency devaluation leads to higher import prices, and thus goods with a high proportion of imported parts rise in price.
6) Steps 2 and 5 creates pressure to production prices, and they rise.
7) / 0) As a consequence, also wholesale prices rise.
(The cycle starts again, Step 7 is also Step 0)
While both the price-salary spiral, the currency devaluation spiral and money printing can explain about 50% of the price increase (or more, in the case of imported goods), the rest is explainable by the fact that all parts in the supply chain continuously rise their prices
more than they would be forced to, to hedge against price increases in their own supply chain. So we have, in addition to these two mechanisms, a lot of small price increases have to be added, from the raw material producer to the retailer, with the wholesale sector probably being the most "greedy" because they are often big companies with high market power.
This creates an inflation inertia. Consumers (including the government) could stop it if they consumed even less, and thus price elasticity increases which makes it difficult to rise prices more. But neither the government nor private consumers have incentives to do this.
Argentina is an extreme example, but I can imagine that long-term stagflation works approximately the same in other countries too. Short-term stagflation, in contrast, is mostly caused by the factors Wind_FURY has cited in the Investopedia article.
It's laughable that the people I talk to that remain in denial of the high-probability of Stagflation that's going to happen in many regions around the world.
I think what those "people in denial" criticize is more the "inflation" part than the "stagnation" part. Of course you could argue that if you had 7% inflation with some economic growth and some months later you have 5% with zero growth, then you're "tending towards stagflation". However, in this case it's likely that the inflation will continue to decrease more due to the economic slowdown, if there are no new external shocks (this could be the case due to the rising oil price for example) or if inflation inertia (like I explained) has already catched on.
*there are three different mechanisms for that in Argentina, not only QE (Central bank buying government bonds) but also direct credits (ATs) and something called "giro de utilidades" which gives the Central Bank the option to directly "give away" money to the government as a gift in months where the currency devaluates. This is of course a quite inflationary process as it's a kind of vicious cycle.